The role of sigmoidoscopy and colonoscopy in the diagnosis and management of lower gastrointestinal disorders: endoscopic findings, therapy, and complications

Solitary Rectal Ulcer Syndrome Coexisting with Colitis Cystica Profunda-Is Mucosal Resection Radical or Not?

We highlight the key diagnostic features of solitary rectal ulcer syndrome coexisting with colitis cysticaprofunda in order to increase awareness of the postoperative recurrence of the diseases.

Colonoscopic Diagnosis of Postoperative Gastrointestinal Bleeding in Patients With Hirschsprung's Disease

Aim: Postoperative lower gastrointestinal bleeding in children with Hirschsprung's Disease (HSCR) is a non-specific symptom, which may be caused by various etiologies. Our current study aims to utilize colonoscopy to diagnose the causes of postoperative hematochezia and to analyze its feasibility, accuracy, and safety. Methods: Twenty-four patients with HSCR with postoperative lower gastrointestinal bleeding or occult blood in the stool were enrolled in this study. The postoperative onset duration, age at examination, accompanied anomalies were recorded. After bowel preparation, all patients underwent colonoscopy. According to visual findings, mucosal biopsy was performed, followed by pathological diagnosis. Further treatment was determined according to the visual findings and pathological diagnosis. All patients were followed up for 6 months including therapeutic outcomes and recurrence of symptoms. Results: The mean onset duration was (221.3 ± 216.8) days postoperatively (ranging from 25 to 768 days). The mean age at examination was (41.0 ± 29.4) months. There was no significant difference in the onset days among each group (all, p > 0.05). Based on visual and pathological findings, there were 11 cases of HSCR associated enterocolitis (HAEC), 4 cases of anastomotic leakage, 7 cases of anastomotic inflammation, 1 case of juvenile polyp, and 1 case of inflammatory pseudopolyp. Intraluminal saline irrigation, thrombin treatment or colorectal polyp electrocision was performed according to intraoperative diagnosis. Patients with HEAC and anastomotic inflammation underwent antibiotics therapy and colorectal irrigation. Patients with leakage underwent reoperation. The highest incidence of accompanied symptoms of diarrhea existed in HEAC group (p = 0.02) and fever in leakage group (p = 0.02), respectively. No perforation or aggravated bleeding occurs in any patients. All patients gained uneventful recovery during follow-up period. Conclusions: Colonoscopy is a safe, accurate and timely examination for HSCR patients with postoperative lower gastrointestinal bleeding. The visual findings and biopsy may provide accurate diagnosis and guide treatment for this subset of patients.

The Rate of Adenocarcinoma in Endoscopically Removed Colorectal Polyps

The purpose of this study was to determine the rate of cancer in a modern series of colorectal polyps. All pathology reports from colon and rectal polyps from 1999 to 2002 were reviewed. Reports of bowel resections, cancer-free polyps, and polyp-free mucosal biopsies were excluded. Polyps were grouped by size, and the rate of adenocarcinoma was determined. χ2 was used for analysis. A total of 4,443 polyps were found, of which 3,225 were adenomatous [2,883 (89.4%) tubular adenomas, 399 (9.3%) tubulo-villous adenomas, 32 (1.0%) villous adenomas, and 11 (0.3%) carcinomas]. The rate of adenocarcinoma by size was 0.07 per cent for polyps <1 cm, 2.41 per cent for polyps 1-2 cm, and 19.35 per cent for polyps >2 cm, representing significantly fewer cancers for each category of polyp size than the accepted standard. The rate of carcinoma in colon polyps is much lower than previously thought and currently stated in many texts. These data do not alter the recommendations for polyp removal, however, failure to retrieve a specimen in a polyp <1 cm in size is unlikely to have an adverse outcome because the chances of malignancy are very low.

The ability of positron emission tomography/computed tomography to detect synchronous colonic cancers in patients with obstructive colorectal cancer

Positron emission tomography/computed tomography (PET/CT) is frequently used to detect colorectal cancer. The present retrospective study assessed the ability of PET/CT to identify synchronous colonic lesions in 72 patients with obstructive colorectal cancer. All patients had undergone surgical resection without undergoing preoperative total colonoscopy (TCS) at the Digestive Disease Center (April 2007 to September 2016), and subsequently underwent TCS of the proximal colon within 2 years post-surgery. A total of 11 patients exhibited 18F-fluorodeoxyglucose uptake during PET/CT of the proximal colon (4 invasive cancers, 3 advanced adenomas and 4 false-positive results), and 61 patients had no uptake in the proximal colon. Among these 61 patients, postoperative TCS revealed 2 invasive cancers and 4 advanced adenomas. The sensitivity of PET/CT for detecting synchronous invasive cancers was 66.6% (4/6), with a specificity of 89.4% (59/66), a positive predictive value of 36.4% (4/11), a negative predictive value of 96.7% (59/61), and an accuracy of 87.5% (63/72). Negative PET/CT results indicated a low probability of synchronous lesions in the proximal colon. Thus, PET/CT may be a useful tool for detecting synchronous colonic cancers in patients with obstructive colon cancer.

Efficacy of 18-fluoro deoxy glucose-positron emission tomography computed tomography for the detection of colonic neoplasia proximal to obstructing colorectal cancer

Identification of secondary colonic neoplasia proximal to obstructing colorectal cancer is essential for determining the range of colorectal resection.We examined the accuracy of 18-fluoro deoxy glucose-positron emission tomography (FDG-PET) for detection of colonic neoplasia.We recruited patients with obstructing colorectal cancer from our registry. Preoperative FDG-PET was performed, and the detection rate for colonic neoplasia was estimated. Preoperative colonoscopy or postoperative colonoscopy within a year after operation was employed as the indexed standard.Ninety-three patients were included in this study. Colonic neoplasia proximal to obstruction was confirmed in 83 cases. The sensitivity and positive predictive value of FDG-PET were 25.3% and 77.8%, respectively. The sensitivity was higher in larger lesions (3.2% for <5 mm, 29.4% for 6-10 mm, 45.5% for 11-20 mm, and 71.4% for >21 mm) and in higher pathological grade lesions (14.6% for low-grade adenoma, 38.5% for high-grade adenoma, 66.7% for carcinoma in situ, and 100% for invasive carcinoma). The round shape in PET images was a predictor for neoplasia, with an area under the curve of 0.75293 at an aspect ratio of 1.70.FDG-PET should be used as a screening modality for invasive colorectal cancer (CRC) proximal to obstructing colorectal cancer.

Molecular biomarkers for an early diagnosis, effective treatment and prognosis of colorectal cancer: Current updates

Colorectal cancer (CRC) is the third most prevalent cancer in the world. Globally, it has been estimated that about 1.4 million new cases of colorectal cancer are diagnosed every year. CRC is a multifactorial disease that arises due to genetics as well as epigenetic alterations in a number of oncogenes, tumor suppressor genes, mismatch repair genes, as well as cell cycle regulating genes in colon mucosal cells. These molecular alterations have been considered as potential CRC biomarkers because they can provide the physicians with diagnostic, prognostic and treatment response information. The goal is to identify relevant, cheap and applicable biomarkers that contribute to patient management decisions, resulting in direct benefits to patients. In this review, we will outline the most currently available and developing tumor tools, and blood molecular biomarkers. Also, we will illustrate their diagnostic, therapeutic and prognostic applications.

DNA methylation patterns as noninvasive biomarkers and targets of epigenetic therapies in colorectal cancer

Aberrant DNA methylation is frequently detected in gastrointestinal tumors, and can therefore potentially be used to screen, diagnose, prognosticate, and predict colorectal cancers (CRCs). Although colonoscopic screening remains the gold standard for CRC screening, this procedure is invasive, expensive, and suffers from poor patient compliance. Methylated DNA is an attractive choice for a biomarker substrate because CRCs harbor hundreds of aberrantly methylated genes. Furthermore, abundance in extracellular environments and resistance to degradation and enrichment in serum, stool, and other noninvasive bodily fluids, allows quantitative measurements of methylated DNA biomarkers. This article describes the most important studies that investigated the efficacy of serum- or stool-derived methylated DNA as population-based screening biomarkers in CRC, details several mechanisms and factors that control DNA methylation, describes a better use of prevailing technologies that discover novel DNA methylation biomarkers, and illustrates the diversity of demethylating agents and their applicability toward clinical impact.

Risk of colon perforation during colonoscopy at Baylor University Medical Center

Colonoscopy is an important procedure in preventing colon cancer. The risk of colonic perforation during colonoscopy at the Baylor University Medical Center (BUMC) Gastrointestinal Laboratory was chosen as a surrogate marker for the safety of colonoscopy. A recent 2-year experience at BUMC was examined and compared with reports in the medical literature. The results are presented here along with a discussion of problems inherent with different health care systems and their ability to accurately track complications. It was concluded that colonoscopy at BUMC is as safe as that reported by comparable health care systems. The risk of perforation at BUMC was 0.57 per 1000 procedures or 1 in 1750 colonoscopies. Continued efforts to make colonoscopy safer are needed.

MR imaging of distal ileal and colorectal chronic inflammatory bowel disease--diagnostic accuracy of 1.5 T and 3 T MRI compared to colonoscopy

PURPOSE

The aim of this study was to investigate the diagnostic accuracy of MR enterography (MRE) for detection of distal ileal and colorectal inflammatory bowel disease (IBD) and to evaluate whether 3 T MRI can provide a higher diagnostic performance compared to 1.5 T.

METHODS

A retrospective review of patients with known or suspected IBD who underwent MRE and colonoscopy within 3 months was performed. For analysis, the bowel was divided into six segments. Compared with colonoscopy, the accuracy values for MRI diagnosis of overall and each magnetic field strength were calculated, and the differences between 1.5 T and 3.0 T were compared. The image quality was scored separately for both field strengths and compared.

RESULTS

Eighty-eight patients were included in the study. On a patient basis, MRE had an overall sensitivity of 92.1 % and specificity of 72.0 %. On a segment basis, the sensitivity and specificity were 79.1 % and 93.6 %, respectively. Concerning severely inflamed segments, per-segment sensitivity increased from 79.1 to 94.7 %. The comparison of accuracy values between the two field strengths showed no statistically significant difference. B1 homogeneity and overall artifacts were not significantly different between 3.0 T and 1.5 T imaging. Compared to colonoscopy, MRI found four more fistulas confirmed at subsequent surgery.

CONCLUSIONS

MRI has a high diagnostic accuracy for detection of distal ileal and colorectal IBD. 3 T MRI can be considered equivalent but not superior compared to 1.5 T imaging in this context. In addition, our findings suggest MRE to be a valuable tool in detecting surgically relevant pathologies (fistulas) with higher accuracy than colonoscopy.

Diagnostic accuracy of magnetic resonance colonography for the evaluation of disease activity and severity in ulcerative colitis: a prospective study

OBJECTIVE

The aim of this study was to determine the diagnostic accuracy of magnetic resonance colonography (MRC) for the evaluation of disease activity and severity in patients with ulcerative colitis (UC) using endoscopy as the reference standard.

METHODS

Fifty patients with UC underwent colonoscopy and MRC for the evaluation of disease activity. All patients were prospectively and consecutively included. Endoscopic activity was evaluated globally and on a segment basis using the modified Baron score (MBS), and also classified as absent, mild to moderate (inflammation without ulcers) or severe (presence of ulceration). MRC parameters evaluated in each segment were: wall thickness, pre- and post-contrast wall signal intensity, relative contrast enhancement (RCE), mural oedema, ulcers, enlarged lymph nodes and the comb sign.

RESULTS

Independent predictors for endoscopic activity on a segment basis were RCE (p=0.006), presence of oedema (p=0.003), enlarged lymph nodes (p<0.001) and the comb sign (p<0.001). A segmental simplified MRC index (MRC-S) ≥ 1 detected endoscopic inflammation with high diagnostic accuracy (sensitivity 87%, specificity 88%, area under the curve (AUC) 0.95; p<0.001). MRC-S index ≥ 2 detected severe lesions with high sensitivity (83%) and specificity (82%) with an AUC of 0.91 (p<0.001). The MRC-S index strongly correlated with the MBS (r=0.81, p<0.001) and with the subjective assessment of the radiologists for the evaluation of disease severity (r=0.77, p<0.001).

CONCLUSIONS

MRC has a high accuracy for the diagnosis of disease activity and severity in UC.

Endoscopy and polyps-diagnostic and therapeutic advances in management

Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.

The Indications for Nonsurgical Management in Patients with Colorectal Perforation after Colonoscopy

Recently, the risk of colonic perforation has been increasing with the increased frequency of advanced therapeutic endoscopy. However, guidelines for the management of colon perforations after colonoscopy have not been established. This study aimed to evaluate the indications for nonsurgical management. This study was conducted as a case–control study with 22 patients who were managed for colorectal perforations after colonoscopy from June 2004 to July 2009. Colonoscopy was performed in 12 patients (54.4%) for diagnostic purposes and 10 (45.5%) for therapeutic reasons. The most common site of perforation was the sigmoid colon (77.3%). Five patients underwent nonsurgical treatment, and 17 patients received surgical treatment. The duration of hospital stay did not differ significantly between the two groups. Abdominal pain and fever were significantly more commonly encountered in the surgical management group ( P = 0.043 and 0.011, respectively). All of the patients who were suitable for nonsurgical treatment were diagnosed within 24 hours and received bowel preparation before the colonoscopy. The nonsurgical treatment of colonic perforation after colonoscopy could be feasible in afebrile patients with less severe abdominal pain. Moreover, cases that were diagnosed within 24 hours and received bowel preparation before colonoscopy were associated with better outcomes.

Sedation, analgesia, and monitoring

Endoscopic procedures are common and sedation is frequently used to minimize anxiety and discomfort, reduce the potential for physical injury during the procedure, and improve overall patient tolerability and satisfaction. In this article, the authors review the variety of options for sedation and analgesia available to the gastroenterologist or surgical endoscopist.

Cardiac ischaemia and rhythm disturbances during elective colonoscopy

BACKGROUND

The number of colonoscopic procedures continues to rise rapidly. With widespread adoption of colonoscopy based bowel screening programmes, this rising trend is set to continue.

AIMS

This study aimed to identify whether elective colonoscopy could provoke cardiac rhythm disturbances and/or myocardial ischaemia, as evidenced by 12 lead Holter ECG recordings and troponin I (cTnI) changes.

MATERIALS AND METHODS

Patients were stratified into three groups based on the presence of cardiac disease or cardiovascular risk factors. They underwent real time 12 lead Holter monitoring before, during and after colonoscopy. Bloods were taken for pre- and post-procedure cTnI estimation.

RESULTS

Holter ECG recordings of the three groups showed a high incidence of new but silent ischaemic and arrhythmic ECG changes during the colonoscopy in patients with documented but stable heart disease and to a lesser extent in those patients with one or more risk factors for heart disease. Three patients had high cTnI concentrations both before and after colonoscopy. Two patients with known heart disease died within 30 days of colonoscopy.

CONCLUSIONS

This study demonstrates for the first time the occurrence of potentially clinically significant ST-T wave changes and rhythm disturbances during elective colonoscopy in patients with known heart disease and to a lesser extent in those patients with a known cardiovascular risk profile.

Invasive cancer in a diminutive rectal polyp amidst internal hemorrhoids detected by rectal retroflexion

A diminutive rectal polyp amidst internal hemorrhoids, detected by rectal retroflexion during colonoscopy, was shown to harbor invasive rectal adenocarcinoma by colonoscopic biopsy. Initially this lesion had appeared to be a relatively innocuous prominent anorectal mucosal fold and was recognized as a diminutive polyp only after careful rectal retroflexion during colonoscopy. This report emphasizes that lesions just above the anorectal junction with atypical endoscopic features for internal hemorrhoids should be carefully examined at rectal retroflexion and that polyps or suspicious lesions amidst internal hemorrhoids identified during colonoscopy should be snared or at least biopsied, even if small. This case report also illustrates how easily an early cancer in a diminutive colonic polyp can be missed when in difficult areas of colonoscopic inspection, such as behind a colonic fold or immediately above the anus.

Nonoperative management of complicated diverticular disease

The complications of diverticular disease of the colon can be divided into those related to inflammatory conditions (diverticular abscess, fistula, and perforation) and those related to noninflammatory conditions (lower gastrointestinal hemorrhage and noninflammatory stricture or obstruction). Nonoperative management of uncomplicated diverticulitis includes bowel rest and antibiotics. For abscesses, percutaneous drainage by radiologic guidance often turns complicated diverticulitis to an uncomplicated condition. In very select instances, fistulas or even perforation may be managed without operation. Strictures may be dilated or stented. Diverticular hemorrhage may be controlled with colonoscopic and angiographic techniques. For colonoscopy, these include cautery, epinephrine injection, and endoclips. For angiography, these include arterial infusion of vasopressin and selective embolization of bleeding vessels. For both diverticulitis and diverticular bleeding, these nonoperative therapeutic modalities may be utilized as a bridge to surgery, or in select instances as a definitive therapy obviating the need for surgery.

Colonoscopic perforation: Incidence, risk factors, management and outcome

This review discusses the incidence, risk factors, management and outcome of colonoscopic perforation (CP). The incidence of CP ranges from 0.016% to 0.2% following diagnostic colonoscopies and could be up to 5% following some colonoscopic interventions. The perforations are frequently related to therapeutic colonoscopies and are associated with patients of advanced age or with multiple comorbidities. Management of CP is mainly based on patients’ clinical grounds and their underlying colorectal diseases. Current therapeutic approaches include conservative management (bowel rest plus the administration of broad-spectrum antibiotics), endoscopic management, and operative management (open or laparoscopic approach). The applications of each treatment are discussed. Overall outcomes of patients with CP are also addressed.

The role of intraoperative carbon dioxide insufflating upper gastrointestinal endoscopy during laparoscopic surgery

BACKGROUND

Intraoperative endoscopy (IOE) is a useful adjunct during laparoscopic gastrointestinal (GI) surgery. However, one potential hazard of IOE is a prolonged bowel distension due to insufflated air, which may cause obstructed surgical exposure and increased postoperative abdominal pain. Recently, carbon dioxide (CO(2)), with its rapid absorptive nature, has been proven effective to minimize prolonged bowel distension in ambulatory/intraoperative colonoscopy. The objectives were to assess the feasibility, safety, and efficacy of CO(2)-insufflating upper GI IOE during laparoscopic surgery.

METHODS

A historical comparison study was performed on the initial ten consecutive patients who underwent CO(2)-insufflating upper GI IOE (CO(2)-IOE) during laparoscopic surgery. The control group consisted of the past 12 consecutive patients who underwent conventional air-insufflating upper GI IOE (air-IOE) during laparoscopic surgery. The following parameters were compared between the two groups: (1) patient demographics; (2) feasibility (% completion of IOE); (3) safety (complications related to IOE, impacts on cardiopulmonary status, including systemic blood pressure, heart rate, and end-tidal CO(2)); (4) efficacy (postoperative residual intestinal gas, time to resume oral intake, and bowel movement). The amounts of post-IOE residual intestinal gas were evaluated and classified on the immediate postoperative abdominal radiographs in a blinded manner.

RESULTS

Patient demographics were comparable between the two groups. IOE was completed in both groups without complications. Adverse effects on cardiopulmonary status were not observed during simultaneous intraperitoneal and intraluminal CO(2) insufflation. In the air-IOE group, one patient was converted to open surgery because of inadequate surgical exposure from prolonged distension of the downstream bowel. The patients in the CO(2)-IOE group had significantly lower grade of postoperative bowel distension than the control group. Postoperative oral intake was resumed earlier in the CO(2)-IOE group.

CONCLUSION

CO(2)-insufflating upper GI IOE during laparoscopic surgery is feasible, safe, and has a practical advantage in minimizing post-IOE bowel distension compared with conventional air-insufflating upper GI IOE.

PET/CT colonography for the preoperative evaluation of the colon proximal to the obstructive colorectal cancer

PURPOSE

This study was designed to evaluate the usefulness of 18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) colonography in preoperative diagnosis of the tumors proximal to obstructive colorectal cancers, which were defined as cancers that cannot be traversed colonoscopically.

METHODS

A whole-body PET/CT protocol for tumor staging and a protocol for CT colonography were integrated into one examination. No cathartic bowel preparation was used before this examination. Thirteen prospective patients with obstructive cancer were examined. We compared the detection rates for obstructive colorectal cancers and tumors proximal to the obstruction using air-inflated PET/CT colonography to intraoperative examinations, histopathologic outcome, and follow-up colonoscopy.

RESULTS

PET/CT colonography correctly identified all 13 primary obstructive colorectal cancers and all 2 synchronous colon cancers proximal to the obstruction. The two synchronous colon cancers detected at PET/CT colonography were confirmed and removed at single-stage surgical procedures. PET/CT colonography was able to localize all colorectal cancers precisely. There were no false-negative or false-positive proximal colorectal cancers by PET/CT colonography. Other preoperative examinations missed the synchronous colon cancers.

CONCLUSIONS

In patients with obstructive colorectal cancers, preoperative PET/CT colonography provided valuable anatomic and functional information of the entire colon to properly address surgery of colorectal cancer.

Endoscopy and magnetic resonance imaging in patients with Crohn's disease: a retrospective single-centre comparative study

OBJECTIVE

There is ongoing debate about which imaging modality is best for patients with inflammatory bowel diseases. Magnetic resonance imaging (MRI) has been successfully used to evaluate the jejunum and the ileum. Because virtual colonoscopy by MRI requires bowel cleansing and/or rectal filling, endoscopy is preferred for assessment of the colon. However, hydro-MRI without special bowel preparation may be sufficient as a diagnostic tool if specifically targeted in the course of a known disease. The aim of this study was retrospectively to assess the correlation of endoscopy, histology and MRI findings for the terminal ileum and the colon in a cohort of patients with Crohn's disease.

MATERIAL AND METHODS

In all, 60 patients with a confirmed diagnosis of Crohn's disease were included in the study. Here, 412 anatomical segments of the colon were analysed by MRI, 401 by endoscopy and 374 by histology.

RESULTS

Presence or absence of inflammation was concordantly diagnosed in 310 segments (77.3%). The highest concordance was found for the terminal ileum and, in patients with previous surgery, the anastomosis. Sensitivity and specificity for MRI versus endoscopy, MRI versus histology and endoscopy versus histology were 64.4%/81.1%, 62.1%/86.2% and 78.2%/80.3%, respectively.

CONCLUSIONS

In a retrospective analysis of patients with Crohn's disease, hydro-MRI assessment of inflammation in anatomical segments of the colon reaches acceptable concordance rates with endoscopy and histology without prior preparation of the bowel. The data justify a prospective controlled trial.

Pathophysiology, clinical presentation, and management of colon cancer

Colon cancer is believed to arise from two types of precursor polyps via two distinct pathways: conventional adenomas by the conventional adenoma-to-carcinoma sequence and serrated adenomas according to the serrated adenoma-to-carcinoma theory. Conventional adenomas arise from mutation of the APC gene; progression to colon cancer is a multistep process. The fundamental genetic defect in serrated adenomas is unknown. Environmental factors can increase the risk for colon cancer. Advanced colon cancer often presents with symptoms, but early colon cancer and premalignant adenomatous polyps commonly are asymptomatic, rendering them difficult to detect and providing the rationale for mass screening of adults over age 50.

Reducing the incidence and mortality of colon cancer: mass screening and colonoscopic polypectomy

Most colon cancers arise from conventional adenomatous polyps (conventional adenoma-to-carcinoma sequence), while some colon cancers appear to arise from the recently recognized serrated adenomatous polyp (serrated adenoma-to-carcinoma theory). Because conventional adenomas and serrated adenomas are usually asymptomatic, mass screening of asymptomatic patients has become the cornerstone for detecting and eliminating these precursor lesions to reduce the risk of colon cancer. Colonoscopy has become the primary screening test because of its high sensitivity and specificity, and the ability to perform polypectomy. Other screening tests include guaiac tests or fecal immunochemical tests (FIT) for fecal occult blood, and flexible sigmoidoscopy. A minimal colonoscopic withdrawal time of 6 minutes is important to maximize polyp detection at colonoscopy. Chromoendoscopy is an experimental technique used to highlight abnormal colonic areas to identify neoplastic tissue and to potentially determine the histology of colonic polyps at colonoscopy based on superficial pit anatomy.

CT colonography: current status and future promise

CT colonography (CTC) is an innovative technology that entails CT examination of the entire colon and computerized processing of the raw data after colon cleansing and colonic distention. CTC could potentially increase the screening rate for colon cancer because of its relative safety, relatively low expense, and greater patient acceptance, but its role in mass colon cancer screening is controversial because of its highly variable sensitivity, the inability to sample polyps for histologic analysis, and lack of therapeutic capabilities. This article reviews the CTC literature, including imaging and adjunctive techniques, radiologic interpretation, procedure indications, contraindications, risks, sensitivity, interpretation pitfalls, and controversies.

Stool detection in colonoscopy videos

Colonoscopy is the accepted screening method for detection of colorectal cancer or its precursor lesions, colorectal polyps. Indeed, colonoscopy has contributed to a decline in the number of colorectal cancer related deaths. However, not all cancers or large polyps are detected at the time of colonoscopy, and methods to investigate why this occurs are needed. One of the main factors affecting the diagnostic accuracy of colonoscopy is the quality of bowel preparation. The quality of bowel cleansing is generally assessed by the quantity of solid or liquid stool in the lumen. Despite a large body of published data on methods that could optimize cleansing, a substantial level of inadequate cleansing occurs in 10% to 75% of patients in randomized controlled trials. In this paper, a machine learning approach to the detection of stool in images of digitized colonoscopy video files is presented. The method involves the classification based on color features using a support vector machine (SVM) classifier. Our experiments show that the proposed stool image classification method is very accurate.

MR colonography without bowel purgation for the assessment of inflammatory bowel diseases: diagnostic accuracy and patient acceptance

BACKGROUND

The purpose of this pilot study was to assess the diagnostic accuracy of MR colonography (MRC) without bowel cleansing regarding its ability to quantify inflammatory bowel disease (IBD). In addition, patient acceptance was compared with conventional colonoscopy (CC).

METHODS

In all, 29 patients with IBD (17 ulcerative colitis; 12 Crohn's disease) were included. While CC was performed after bowel cleansing as the gold standard, MRC was based on a fecal tagging technique and performed 48-72 hours prior to CC. The presence of inflammation in each of 7 ileocolonic segments was rated for every procedure. Patients evaluated both modalities and dedicated aspects of the examination according to a 10-point-scale (1 = good, 10 = poor acceptance). Furthermore, preferences for future examinations were investigated.

RESULTS

Inflammatory segments were found by means of CC in 23 and by MRC in 14 patients. Overall sensitivity and specificity of MRC in a segment-based detection were 32% and 88%, respectively. Concerning severely inflamed segments, sensitivity increased to 53% for MRC. Overall acceptance of CC was significantly higher compared to MRC (mean value (mv) for MRT = 6.0; CC = 4.1; P = 0.003). For MRC, the placement of the rectal tube (mv = 7.3), and for CC bowel purgation (mv = 6.5), were rated as the most unpleasant. A total of 67% of patients voted for CC as the favorable tool for future examinations.

CONCLUSIONS

The presented data indicate that 'fecal tagging MRC' is not suitable for an adequate quantification of inflammatory diseases of the large bowel. Furthermore, overall acceptance of endoscopic colonoscopy was superior to MRC.

Use of neostigmine to relieve a suspected colonic pseudoobstruction in pregnancy

Neostigmine is a treatment option for colonic pseudoobstruction. However, experience in using neostigmine for this indication in pregnant women is limited. We present a case of a woman with an estimated fetal gestational age of 34 weeks presented with what was believed to be a pseudoobstruction and when conservative management failed, neostigmine was administered with no adverse side effects. Ultimately, the patient was found to have a mechanical obstruction and we discuss the challenges in making this diagnosis in pregnancy. Neostigmine may be a viable alternative to colonoscopy in pregnant women for whom mechanical obstruction is properly excluded.

Role of intravenously administered hyoscine butyl bromide in retrograde terminal ileoscopy: A randomized, double-blinded, placebo-controlled trial

AIM: To evaluate the role of hyoscine butyl bromide in facilitating retrograde ileoscopy.

METHODS: Retrograde terminal ileoscopy was attempted in 200 consecutive patients undergoing colonoscopy. After intubation of the cecum and visualization of the ileocecal valve, hyoscine butyl bromide injection or normal saline was given intravenously to the patients in a double blind random fashion. The pulse rate and oxygen saturation were measured continuously. After completion of the procedure, endoscopists were then asked to score the ease of intubation and the ease of visualization of the terminal ileum on a visual scale of 1 to 10. The patients were also asked to score the pain after receiving hyoscine butyl bromide injection on a score of 1 to 10.

RESULTS: Terminal ileoscopy could be performed in 188 patients. The mean (SD) visual analogue score for the ease of intubation of the cecum was 7.4 (0.65) in the injection group and 5.9 (0.8) in the placebo group (P < 0.001). The mean (SD) length of ileum visualized in the injection group was 14.4 (3.3) cm and 10.4 (2.7) cm in the placebo group (P < 0.001). The mean (SD) visual analogue score for ease of visualization of the terminal ileum was 7.5 (0.69) in the injection group and 5.9 (0.7) in the placebo group (P < 0.001). The pain score experienced by the patients was 6.5 (0.7) in the injection group and 6.7 (0.69) in the placebo group (P < 0.008). Although the pulse rate increased significantly in patients receiving the drug, no statistically significant difference was noted in the oxygen saturation between the two groups either before or after administration of the drug. No complications were observed in either of the groups.

CONCLUSION: Hyoscine butyl bromide injection is a useful adjunct in helping the intubation and visualization of terminal ileum during colonoscopy.

Minimizing endoscopic complications: colonoscopic polypectomy

Current polypectomy tools and techniques are inadequate to prevent all postpolypectomy bleeding, perforation, and postpolypectomy syndrome; however, adherence to certain principles can substantially reduce the risk of these complications. This review does not focus on technical aspects of colonoscopy that are directed toward preventing complications of failed eradication. Rather, the authors focus on the classic complications of bleeding, perforation, and their prevention. New technologies that could further reduce or eliminate perforation and bleeding after polypectomy are sorely needed.

Management of complications in surgery of the colon

BACKGROUND

General surgeons are frequently confronted with colorectal diseases in their daily practice, whereby colorectal cancer is the second most common malignant tumour, with almost 5000 new cases every year in Austria. The incidence of benign colon disorders requiring surgery (e.g. colon polyps, sigmoid diverticulitis) is also increasing. The first aim in colon surgery should be to avoid complications and if they occur to treat them properly.

METHODS

We basically distinguish between general and special complications. As general complications, prevention of malnutrition and support of the immune system should receive special attention. As the number of elderly patients increases, so does the risk not only of thrombembolic complications but also of critical cardiocirculatory situations, and renal and hepatic failure. Special complications depend either on the type of surgery (laparoscopic assisted, conventional open surgery) or the techniques employed (stapled, hand sutured). Handling of the tissue also plays a major role (e.g. dry versus wet pads).

RESULTS

Shortening of the postoperative stay decreases both hospital costs and the incidence of infections, meaning that minimally invasive surgery and postoperative "fast track nutrition" should be promoted. Emergency operations should be avoided (e.g. bridging through colonic stents), as morbidity and mortality are clearly increased in comparison to (semi-) elective operations. During the operation itself, new equipment and techniques (such as Ultracision®, Ligasure®) as well as a well coordinated team help to reduce complications and duration of surgery.

CONCLUSIONS

To avoid is better than to repair. If complications do occur, appropriate surgical and intensive - care measures should be taken immediately.

Colitis cystica profunda and solitary rectal ulcer syndrome-polypoid variant: Two confusing clinical conditions

Colitis cystica profunda and solitary rectal ulcer syndrome-polyoid variant are related chronic benign disorders with characteristic histological features. However, the clinical and endoscopic settings are confusing and misleading, suggesting other rectal conditions. We report a case of colitis cystica profunda and solitary rectal ulcer syndrome-polypoid variant that was misdiagnosed initially as an ulcerative proctitis. Since an occult malignancy could not be ruled out by superficial biopsies, the mass was removed by full-thickness transanal excision.

Complications of Abdominal and Pelvic Procedures: Computed Tomographic Diagnosis

The postprocedural period is a critical time in which serious complications can manifest. Localization of suspected complications following abdominal and pelvic procedures can be difficult on clinical evaluation alone. For example, abdominal pain after a colonoscopy may vary in etiology and can result from simple colonic spasm to colonic perforation, hemoperitoneum, or even splenic rupture. Vague abdominal pain following a renal biopsy may be due to minimal postprocedural bleeding into and around the kidney or may be due to potentially life-threatening hemorrhage. In such patients, computed tomography can play a crucial role in the rapid identification of complications as well guidance of subsequent patient management. The purpose of this article is to demonstrate the benefit of computed tomography-assisted diagnosis of complications associated with routine procedures performed on or throughout the abdomen and pelvis, including cardiac catheterization, colonoscopy, endoscopy, percutaneous biopsy, and interventional radiology procedures.

Survey of consent practices for inpatient colonoscopy and endoscopic retrograde cholangiopancreatography at a tertiary referral center

BACKGROUND

The purpose of the present paper was to determine informed consent practices for inpatient, open-access colonoscopy and endoscopic retrograde cholangiopancreatography (ERCP) at a tertiary referral center.

METHODS

A two-part prospective study incorporating (i) an audit of consent practices for colonoscopy and ERCP; and (ii) a questionnaire directed at gastroenterologists and interns regarding information imparted to patients in the process of acquiring informed consent, was undertaken at Sir Charles Gairdner Hospital, Western Australia. Study subjects consisted of inpatients undergoing open-access colonoscopy and/or ERCP at the study center commencing May 2003; and gastroenterologists and interns at the study center.

RESULTS

Written consent was obtained by junior medical staff in 89% of cases. Response rates for the questionnaire was 100% from interns, and 91% from gastroenterologists. Of interns surveyed, 93% had witnessed a colonoscopy, and 59% had witnessed an ERCP. For 12% of interns, colonoscopic bleeding or perforation were not always mentioned. Colonoscopy failure rate and perforation were overestimated by 51% and 63% of interns, respectively. Only 56% of interns always mentioned pancreatitis as a complication of ERCP. The rate of post-ERCP pancreatitis was overestimated by 25% of interns. Only 40% of gastroenterologists always provided additional information to patients whose consent was obtained by someone else. Written material was not routinely provided for patients. Consent was usually obtained on the day of the procedure.

CONCLUSIONS

Written consent for inpatients undergoing open-access colonoscopy and ERCP is rarely obtained by the proceduralist. There is substantial variability in the information provided to patients. Guidelines are required to ensure best practice in this area.

Endoscopic mucosal resection (EMR) in the management of large colo-rectal polyps

BACKGROUND

Colonoscopic polypectomy plays a major role in preventing colo-rectal cancer. However, resection of sessile, broad-based pedunculated and flat lesions carries a high risk of perforation. Endoscopic Mucosal Resection (EMR) may significantly reduce this risk. We aim to assess the safety and efficacy of EMR in our unit.

PATIENTS AND METHODS

A review of a prospective database over a 3-year period identified 87 patients who underwent endoscopic polypectomy for polyps in sizes from 10 to 50 mm, performed by two experienced endoscopists. A total of 33 EMRs were performed on 30 lesions in 24 of these patients.

RESULTS

Median size of lesions was 20 mm. Most were located in the rectum and sigmoid. 22 lesions were resected en-bloc while 8 were resected piecemeal. Histologically these lesions were predominantly adenomatous polyps. An incidental focus of adenocarcinoma was found in 7 lesions. Histologically complete excision was achieved in 10 lesions. Although histological completeness of excision was not confirmed in 19 lesions, repeat colonoscopy confirmed successful excision. Only one lesion was incompletely excised requiring surgical resection. Bleeding occurred during 2 EMRs, both times successfully controlled by further injection of adrenaline locally. There was no case of bowel perforation. Further surveillance colonoscopy was performed according to established guidelines. Median follow-up period was 21 months. None of the patients diagnosed with adenocarcinoma showed any evidence of recurrence.

CONCLUSION

Within our unit endoscopic mucosal resection appeared to be safe and effective procedure for resecting large colorectal polyps not suitable for conventional polypectomy. This data would support prompt referral of lesions fulfilling these criteria to specialist units offering this service to avoid unnecessary surgery.

Carbon dioxide insufflation attenuates parietal blood flow obstruction in distended colon

BACKGROUND

Bowel distention after colonoscopy has been considered as a cause of blood flow disturbance. Carbon dioxide (CO2), with its higher absorbability and vasodilating effect, may reduce parietal blood flow disturbance of distended colon when used for intraluminal insufflation instead of air. The purpose of this study was to assess parietal blood flow of the colon distended with intraluminal air/CO2 insufflation.

METHODS

A 5-cm segment of rat colon was insufflated with either air (air group) or CO2 (CO2 group). Two insufflation methods were employed: temporary insufflation up to an intraluminal pressure of 60 mmHg and continuous insufflation at a pressure of 5, 15, and 30 mmHg. Bowel distention and parietal blood flow measured by laser Doppler imaging were evaluated.

RESULTS

For temporary insufflation, bowel distention was prolonged in the air group, whereas it rapidly resolved in the CO2 group. Parietal blood flow decreased in both groups; however, it recovered within 5 min in the CO2 group. For continuous insufflation, under 5 mmHg insufflation, blood flow decreased in the air group, whereas it increased in the CO2 group. Blood flow decreased in both groups under 15 mmHg insufflation; however, it decreased less in the CO2 group. There was a reverse relationship between insufflation pressure and blood flow difference. Inhibition of nitric oxide synthase, ATP-sensitive K+ channel, or heme oxygenase was ineffective against a CO2-induced increase in blood flow.

CONCLUSION

CO2 insufflation preserved parietal blood flow not only by rapid resolution of bowel distention but also by its potential vasodilative effect.

The management of lower gastrointestinal hemorrhage

PURPOSE

Gastrointestinal hemorrhage is a common clinical problem, which accounts for approximately 1 to 2 percent of acute hospital admissions. The colon is responsible for approximately 87 to 95 percent of all cases of lower gastrointestinal bleeding, with the remaining cases arising in the small bowel. The etiology, diagnostic evaluation, management, and treatment options available for lower gastrointestinal hemorrhage were reviewed.

METHODS

A review of lower gastrointestinal bleeding was performed, which discussed the most common etiologies with a few rare and unusual causes. The current literature about different diagnostic techniques, management problems, and therapeutic options was reviewed. Current management strategies and treatment options for the many causes of lower gastrointestinal bleeding will be reviewed.

RESULTS

A review of the different causes of lower gastrointestinal hemorrhage and available diagnostic studies was performed. Management strategies based on the etiology of the bleeding and results of the diagnostic studies were discussed. An algorithm was provided to develop a diagnostic and therapeutic treatment strategy for lower gastrointestinal hemorrhage.

CONCLUSIONS

Lower gastrointestinal hemorrhage can be a difficult and frustrating problem to both the clinician and the patient. Knowledge of the available diagnostic tests to help identify the source of bleeding is essential to the practicing clinician. Once the source is identified, management strategies and available treatment options need to be specific for each individual case. This review will aid the practicing physician in developing an algorithm for lower gastrointestinal hemorrhage.

Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study

BACKGROUND

The quality of colon cleansing is a major determinant of quality of colonoscopy. To our knowledge, the impact of bowel preparation on the quality of colonoscopy has not been assessed prospectively in a large multicenter study. Therefore, this study assessed the factors that determine colon-cleansing quality and the impact of cleansing quality on the technical performance and diagnostic yield of colonoscopy.

METHODS

Twenty-one centers from 11 countries participated in this prospective observational study. Colon-cleansing quality was assessed on a 5-point scale and was categorized on 3 levels. The clinical indication for colonoscopy, diagnoses, and technical parameters related to colonoscopy were recorded.

RESULTS

A total of 5832 patients were included in the study (48.7% men, mean age 57.6 [15.9] years). Cleansing quality was lower in elderly patients and in patients in the hospital. Procedures in poorly prepared patients were longer, more difficult, and more often incomplete. The detection of polyps of any size depended on cleansing quality: odds ratio (OR) 1.73: 95% confidence interval (CI)[1.28, 2.36] for intermediate-quality compared with low-quality preparation; and OR 1.46: 95% CI[1.11, 1.93] for high-quality compared with low-quality preparation. For polyps >10 mm in size, corresponding ORs were 1.0 for low-quality cleansing, OR 1.83: 95% CI[1.11, 3.05] for intermediate-quality cleansing, and OR 1.72: 95% CI[1.11, 2.67] for high-quality cleansing. Cancers were not detected less frequently in the case of poor preparation.

CONCLUSIONS

Cleansing quality critically determines quality, difficulty, speed, and completeness of colonoscopy, and is lower in hospitalized patients and patients with higher levels of comorbid conditions. The proportion of patients who undergo polypectomy increases with higher cleansing quality, whereas colon cancer detection does not seem to critically depend on the quality of bowel preparation.

From Colonic Polyps to Colon Cancer: Pathophysiology, Clinical Presentation, and Diagnosis

Epidemiologists, basic researchers, clinicians, and public health administrators unite! Develop and implement a simple, safe, and effective preventive and screening test for colon cancer. The public will willingly and enthusiastically accept such a test. Many thousands of lives are at stake every year.

18-Fluorodeoxyglucose positron emission tomography has limited sensitivity for colonic adenoma and early stage colon cancer

BACKGROUND

18-Fluorodeoxyglucose positron emission tomography (PET) is used clinically to detect recurrent colon cancer after surgical resection, but the sensitivity of PET for premalignant colon lesions and early stage colon cancer is not well defined.

METHODS

In a prospective study, 45 patients with a total of 58 colonic neoplasms, including premalignant polyps, premalignant, flat lesions, and early stage cancers, were evaluated by PET.

RESULTS

The sensitivity of PET for cancer was 62% (8/13). PET detected 100% (7/7) of cancers 2 cm or larger but only 17% (1/6) of cancers smaller than 2 cm. PET detected 23% (3/13) of flat, premalignant lesions; 70% (7/10) of protruded, premalignant lesions 3 cm or larger; 38% (3/8) of protruded, premalignant lesions between 2 and 2.9 cm; and 14% (2/14) of protruded, premalignant lesions between 1 and 1.9 cm. There was no false-positive PET reading.

CONCLUSIONS

PET has limited sensitivity for flat, premalignant lesions; protruded, premalignant lesions smaller than 3 cm; and colon cancers smaller than 2 cm.

The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps

A review of the pathophysiology, clinical presentation, and diagnosis of colon cancer and colonic polyps is important and timely. This field is rapidly changing because of breakthroughs in the molecular basis of carcinogenesis and in the technology for colon cancer detection and treatment. This article reviews colon cancer and colonic polyps, with a focus on recent dramatic advances, to help the pri-mary care physician and internist appropriately refer patients for screening colonoscopy and intelligently evaluate colonoscopic findings to reduce the mortality from this cancer.

Safety and efficacy of colonoscopy after myocardial infarction: an analysis of 100 study patients and 100 control patients at two tertiary cardiac referral hospitals

BACKGROUND

The purpose of this study is to analyze the risks vs. the benefits of colonoscopy soon after myocardial infarction.

METHODS

A total of 100 consecutive patients undergoing colonoscopy within 30 days after myocardial infarction at two large tertiary cardiac referral hospitals were studied. The study group was compared with 100 control patients with neither myocardial infarction nor unstable angina during the preceding 6 months (matched for age, colonoscopy indication, and colonoscopist) who underwent colonoscopy.

RESULTS

Indications for colonoscopy were bleeding per rectum (37 patients), fecal occult blood (36 patients, hematocrit < 30% in 25), iron deficiency anemia (11 patients, hematocrit < 25% in 9), and other (16 patients). Colonoscopy was performed at a mean of 15.5 (8.3) days after myocardial infarction. Two patients underwent colonoscopic colonic decompression. Colonoscopy was diagnostic in 46 (47%) of the study patients vs. 41% of the control patients ( p = 0.47, chi-square test). The relative rate of ischemic colitis was significantly higher in study vs. control patients (14 vs. 2, p < 0.005). Other diagnoses in study patients were the following: colon cancer (8), bleeding internal hemorrhoids (5), pseudomembranous colitis (5), high-risk adenomatous polyp (large or villous histopathology) (4), and other (10). Urgent colonoscopy was diagnostic in 63% of cases. Twenty-three patients had a major therapeutic benefit consequent to colonoscopy, including colon cancer surgery in 5. Study patients were significantly sicker than control patients (APACHE II score 9.9 [4.3] vs. 7.4 [2.8], p < 0.0001) and suffered significantly more colonoscopic complications compared with control patients (9 vs. 1; OR 5.2: 95% CI [1.2, 9.8], p < 0.03). Minor complications without clinical sequelae occurred in 8 study patients (asymptomatic hypotension or bradycardia). One major complication occurred in this group that was probably not procedure related.

CONCLUSIONS

Colonoscopy in patients with a recent myocardial infarction is associated with a higher rate of minor, transient, and primarily cardiovascular complications compared with control patients but is relatively infrequently associated with major complications. Colonoscopy is beneficial and indicated after myocardial infarction, despite a higher risk, in certain circumstances. The relative frequency of ischemic colitis was relatively high in study patients.

Clinical relevance of transabdominal ultrasonography and magnetic resonance imaging in patients with inflammatory bowel disease of the terminal ileum and large bowel

BACKGROUND

Ileocolonoscopy represents the diagnostic standard in the work-up of patients with inflammatory bowel diseases (IBD). Patients are often reluctant to be colonoscoped because of the invasiveness and pain sensation during colonoscopy.

AIMS

To compare the usefulness oftransabdominal ultrasound (US) and magnetic resonance imaging (MRI) in assessing disease extension and activity in patients with IBD restricted to the terminal ileum and large bowel.

PATIENTS AND METHODS

61 patients with IBD [37 Crohn's disease (CD) and 24 ulcerative colitis (UC)] were prospectively studied. All patients underwent clinical and laboratory assessment, ileocolonoscopy, transabdominal sonography, and MRI within 5 days. Involved bowel segments were defined as those with bowel wall thickness >3 mm and increased Doppler signal on US or contrast enhancement of the bowel wall on MRI. To compare disease activity endoscopic, MRI and US findings were graded with newly developed scores.

RESULTS

The segment-by-segment analysis revealed an overall accuracy of 89% for US and 73% for MRI in identifying active IBD. The accuracy was better in patients with UC than in patients with CD for both US and MRI. The endoscopic activity index (EAI) correlated stronger with the US activity index (r = 0.884) than with the MRI activity index (r = 0.344). The correlation of US and MRI activity indices with EAI was better in patients with UC compared with patients with CD. All three imaging methods showed a significant correlation with clinical disease activity in patients with UC but not in patients with CD.

CONCLUSION

This study provides strong evidence that US should be considered as a first-choice method for follow-up of patients with IBD of the terminal ileum and large bowel.

Colonic toxicity of administered drugs and chemicals

Although uncommon, medication-induced colonotoxicity is important to recognize because medication cessation generally leads to prompt clinical improvement, while medication continuation results in disease exacerbation. This review categorizes the association between medications and colonotoxicity as "well-established" or "probable," according to the following criteria: total number of reported cases, number of different research groups reporting an association, experimental and pharmacologic evidence of an association, and validity of an association in each reported case. Cocaine, ergotamine, estrogen, sodium polystyrene, alosetron, amphetamines, pseudoephedrine, and vasopressin are associated with colonic ischemia. The mechanisms include vasospasm, thrombogenesis, and shunting of blood from mesenteric vessels. Narcotics, phenothiazines, vincristine, atropine, nifedipine, and tricyclic antidepressants are associated with colonic pseudo-obstruction. The mechanisms include antagonizing prokinetic neurotransmitters, stimulating antikinetic neurotransmitters, promoting dysmotility, relaxing smooth muscle, and injuring enteric neurons. Numerous antibiotics are associated with pseudomembranous colitis; ampicillin is associated with hemorrhagic colitis; chemotherapy is associated with neutropenic colitis; and deferoxamine is associated with Yersinia enterocolitis. Mechanisms of these toxicities include altering normal bowel flora, weakening immunologic defenses, promoting microorganism virulence, and mucosal injury. Gold compounds, nonsteroidal antiinflammatory drugs, alpha-methyldopa, salicylates, and sulfasalazine are associated with an inflammatory or cytotoxic colitis. The mechanisms include direct mucosal cytotoxicity, antimetabolite effects, or drug allergy. Nonsteroidal antiinflammatory drugs, cyclo 3 fort, flutamide, lansoprazole, and ticlopidine are associated with lymphocytic colitis. The mechanisms include immunologic activation or attenuated immunologic defenses. Chronic cathartic use leads to colonic hypomotility and abdominal distention. Intrarectally administered corrosive compounds can produce a toxic colitis.