Clinical Implications of Microscopic Colitis Isolated to Polyps

Microscopic colitis is generally identified on random colon biopsies performed for chronic diarrhea, but rarely incidental polyps have histologic features of microscopic colitis. We compared patients with polypoid microscopic colitis to control patients with conventional polyps to determine the implications of polypoid microscopic colitis.

Medical records were searched for patients without prior or concurrent microscopic colitis who were found to have polypoid microscopic colitis. For each patient with polypoid microscopic colitis, one patient with conventional polyps was selected as a control. We reviewed the histologic features of each polypoid microscopic colitis specimen, and evaluated endoscopic and clinical findings for polypoid microscopic colitis patients and controls.

Twenty-six patients with polypoid microscopic colitis were identified with histologic features of collagenous colitis in 8 patients (31%) and lymphocytic colitis in 18 patients (69%). Polypoid microscopic colitis was unifocal in 14 patients (54%) and multifocal in 12 patients (46%). Patients with polypoid microscopic colitis were older than control patients (median age = 60 years vs 66 years, P = .04). On follow-up 7 patients with polypoid microscopic colitis (33%) developed chronic diarrhea compared to 3 (12%) controls (P = .16). Of patients with follow-up biopsies, 1 patient with polypoid microscopic colitis (13%) and no control patients developed microscopic colitis (P = 1).

Polypoid microscopic colitis may be identified in asymptomatic patients and most patients do not develop chronic diarrhea, but some patients with polypoid microscopic colitis develop diarrhea (33% vs 12% in controls) or conventional microscopic colitis on follow-up. Thus pathologists should distinguish polypoid microscopic colitis from conventional microscopic colitis but may inform clinicians of the uncertain association with chronic diarrhea to guide decisions regarding follow-up.

Microscopic colitis found together with celiac disease in a female population is associated with one episode of lymphocytic colitis

BACKGROUND

Microscopic colitis (MC) is considered a chronic disease associated with autoimmune disease, smoking, and drugs. The aim was to examine the association between MC and celiac disease, adjusted for smoking, considering subtypes and clinical course of the disease in a retrospectively collected female cohort.

METHODS

Women (n = 240), ≤ 73 years, diagnosed as MC in medical records or pathological registers were invited. One hundred and fifty-eight women accepted to be included. Participants completed a study questionnaire about sociodemographic factors, lifestyle habits, and medical history; the Rome III questionnaire; and the visual analog scale for irritable bowel syndrome (VAS-IBS). Participants were categorized into collagenous colitis (CC) (n = 92) and lymphocytic colitis (LC) (n = 66) or MC with one episode of the disease (n = 70) and refractory MC (n = 88). Presence of IBS-like symptoms were noted. Blood samples were collected and analyzed for anti-transglutaminase antibodies. Differences between groups were calculated and logistic regression was adjusted for smoking habits.

RESULTS

MC and celiac disease debuted simultaneously in half of the cases. Celiac disease was most prevalent in LC (12.1% vs. 3.3%; p = 0.05) and MC with one episode (12.9% vs. 2.3%; p = 0.01). Anti-transglutaminase antibodies were found in one patient with one episode of MC. Corticosteroid use was most often found in CC (37.0% vs. 21.2%; p = 0.037) and refractory MC (38.6% vs. 20.0%; p = 0.015). Past smokers were most prevalent in patients with one episode of MC (54.3 vs. 29.5%; p = 0.007). Current smoking was the smoking habit with highest prevalence of IBS-like symptoms. When adjusted for smoking habits, celiac disease was associated with LC (OR: 4.222; 95% CI: 1.020-17.469; p = 0.047) and tended to be inversely associated with refractory MC (OR: 0.210; 95% CI: 0.042-1.506; p = 0.058).

CONCLUSION

Celiac disease is most common in patients with one episode of LC. The question remains whether LC in combination with celiac disease should be classified as celiac disease or two different entities.

Microscopic colitis related to food supplement containing turmeric: a review of 3 cases

Microscopic colitis is a chronic inflammatory disorder of the colon characterized by microscopic changes in the intestinal lining. Turmeric, a commonly used spice, is generally regarded as beneficial for digestive and articular health thanks to its anti-inflammatory properties. No cases of microscopic colitis under a food supplement containing turmeric has been previously described in the literature. This article highlights 3 cases where the consumption of a specific turmeric-based supplement caused microscopic colitis. Each of them complained about profuse watery diarrhea shortly after initiating the food supplement containing turmeric. Ileo-colonoscopies with biopsies confirmed the diagnosis of microscopic colitis, with two cases classified as lymphocytic colitis and the third as collagenous colitis. Following the discontinuation of the supplement, all patients experienced a resolution of their symptoms within a few days. Subsequent control biopsies for the three patients confirmed the resolution of microscopic colitis.

What do we know today about drug-induced microscopic colitis? A case of lymphocytic colitis on olmesartan

Microscopic colitis is part of the differential diagnosis of chronic watery diarrhea. Colonoscopy discloses a normal looking mucosa, therefore its diagnosis is based on histology of colonic biopsies. Two main phenotypes are distinguished: collagenous colitis and lymphocytic colitis. A third entity, incomplete microscopic colitis or unspecified microscopic colitis has been reported in the literature. It affects preferentially women over 60 years of age and its association with certain drugs is increasingly established. In case of suspected drug-induced microscopic colitis, identification of the responsible drug is a key to management. After discontinuation of the suspected drug, the gold standard of treatment is budesonide both for induction and for maintenance in case of clinical relapse, as is often the case after discontinuation. Therapy with immunomodulators, biologics, or surgery is reserved for refractory forms of microscopic colitis after multidisciplinary consultation. Through the clinical case of colitis on olmesartan, we will review the latest recommendations on drug-induced microscopic colitis.

Frequency And Risk Factors Of Microscopic Colitis As A Cause Of Chronic Watery Diarrhoea

BACKGROUND

Microscopic colitis (MC) is one of the most underdiagnosed conditions leading to chronic watery diarrhoea in patients worldwide. This is the first study of this kind in Pakistan and we aimed to calculate the frequency as well as study the risk factors behind the disease.

METHODS

This was a prospective cross-sectional study in a tertiary care hospital in Pakistan. A total of 58 participants with chronic watery diarrhoea who had normal colonoscopy were recruited for the study and biopsies were obtained for diagnosing MC.

RESULTS

2 participants out of 58 (3.4%) had biopsy proven microscopic colitis; one patient had a lymphocytic colitis variant and the other had a collagenous colitis variant. The average score based on the MC scoring system was 7.53 in the entire study group. The patient with lymphocytic colitis had a score of 06 while the patient with collagenous colitis had a score of 8.

CONCLUSIONS

The frequency of microscopic colitis was found to be 3.4% of all cases of chronic watery diarrhoea. A link between MC and autoimmune diseases was also observed. However, we had a limited sample size and encouraged future studies to employ a larger sample size to get a multifaceted look at the disease process.

Microscopic colitis: Etiopathology, diagnosis, and rational management

Microscopic colitis is an inflammatory bowel disease divided into two subtypes: collagenous colitis and lymphocytic colitis. With an increasing incidence of microscopic colitis exceeding those of ulcerative and Crohn's disease among elderly people in some countries, microscopic colitis is a debilitating life experience. Therefore, physicians should be familiar with its clinical features and management strategies because the disease deserves the same attention as the classical inflammatory bowel diseases. Here, state-of-the-art knowledge of microscopic colitis is provided from a global perspective with reference to etiopathology and how to establish the diagnosis with the overall aim to create awareness and improve rational management in clinical practice. The immune system and a dysregulated immune response seem to play a key role combined with risk factors (e.g. cigarette smoking) in genetically predisposed individuals. The symptoms are characterized by recurrent or chronic nonbloody, watery diarrhea, urgency, weight loss, and a female preponderance. As biomarkers are absent, the diagnosis relies on colonoscopy with a histological assessment of biopsy specimens from all parts of the colon. Although the disease is not associated with a risk of colorectal cancer, a recent nationwide, population-based cohort study found an increased risk of lymphoma and lung cancer. Budesonide is the first-line therapy for management, whereas immunomodulatory drugs (including biologics) and drugs with antidiarrheal properties may be indicated in those failing, dependent, or intolerant to budesonide. In microscopic colitis induced by checkpoint inhibitors, a drug class used increasingly for a wide range of malignancies, a more aggressive therapeutic approach with biologics introduced early seems reasonable. However, particular attention needs to be drawn to the existence of incomplete forms of microscopic colitis with the risk of being overlooked in routine clinical settings.

[Lymphocytic colitis caused by medicine ingredient modification]

A 49-year-old woman was referred to our hospital for further evaluation and treatment of diarrhea. Colonoscopic findings revealed indistinct vascular patterns and extensive edema in a colon segment, and white granular mucosa and crack-like appearance in the sigmoid colon and rectum. She was diagnosed with lymphocytic colitis (LC) based on lymphocytic infiltration into the epithelium on histopathological examination. Diarrhea symptoms resolved after long-term medication withdrawal. This medicine's composition was changed 4 years ago and this modification possibly triggered LC.

Lymphocytic and collagenous colitis in children and adolescents: Comprehensive clinicopathologic analysis with long-term follow-up

Microscopic colitis (MC) is characterized by chronic watery diarrhea, endoscopically normal findings, and abnormal histology. While mostly encountered in adults, pediatric cases are rare and may show varying presentations. Our pathology data system was searched from 1984 to 2019 for patients ≤18 years of age with a lymphocytic colitis (LC) or collagenous colitis (CC) pattern of injury. Twenty-seven cases (23 LC and 4 CC) were retrieved. LC was more prevalent than CC (85% vs 15%, respectively) and affected slightly younger individuals (mean, 9.8 years versus 12.25 years). Immune dysregulation was documented in 11 (41%) patients. Most patients presented with watery diarrhea (n = 26, 96%) and either abdominal pain (n = 18, 67%), nausea/vomiting (n = 5, 19%), flatulence (n = 6, 22%), and/or weight loss (n = 1, 4%). A subset of patients (n = 10, 37%) demonstrated endoscopic abnormalities. Histologically, some patients with LC and CC displayed focal cryptitis or crypt abscess formation (n = 7, 26%) and focally increased crypt apoptosis (n = 9, 33%) in the absence of chronic injury. Clinical follow-up data were available for 23 (85%) patients with variable clinical responses recorded. Only 8 patients experienced complete symptom resolution. Twelve patients (11 LC and 1 CC) had subsequent biopsy material; of which, one developed histologic features of inflammatory bowel disease and another was found to have a CTLA-4 deficiency. Our study shows that pediatric patients with MC may have atypical clinical, histologic, and endoscopic findings and variable clinical responses. Underlying inflammatory and/or genetic conditions may be eventually unmasked, and genetic testing may be helpful in a small subset of patients.

[Concurrent lymphocytic colitis and microscopic enteritis in patients with chronic diarrhea]

INTRODUCTION

Lymphocytic colitis and microscopic enteritis are relatively common causes of chronic diarrhea and it is characterized by an intraepithelial lymphocytic infiltrate. There have been no previous reports of coexistence between these 2 pathologies.

OBJECTIVE

To describe histological and clinical characteristic in patients with coexistence of lymphocytic colitis and microscopic enteritis.

MATERIAL AND METHODS

All cases with simultaneous diagnosis of lymphocytic duodenosis and lymphocytic colitis were reevaluated during lapse time 2010-2016 in hospital Daniel Carrion. The slides were reviewed by 3 pathologists and clinical information was obtained from clinical records. Expression of CD3 and CD8 was detected in 6 cases by immunohistochemical assays.

RESULTS

A total of 35 patients with coexistence of lymphocytic duodenitis and lymphocytic colitis were selected of the pathology archives, 80% were females, Anemia was identified in 28.5% of patients. Blastocysitis hominis infestation was identified in 31.8%. The mean intraepithelial lymphocyte CD8 and CD3 positive was 40% in microscopic enteritis, while the mean intraepithelial lymphocyte CD3 positive was 37.2% and CD8 positive was 29.2% Additionally, lymphocytic ileitis was diagnosed in 11 of our cases. Eosinophilic colitis was diagnosed in 9 cases of lymphocytic colitis Conclusion: We found that lymphocytic colitis, microscopic enteritis and even lymphocytic ileitis can coexist in a group of patients with chronic diarrhea. These findings bring the question if this concurrence of both pathologies constituted a more generalized gastrointestinal disorder, involving both the large and the small intestines.

Lymphocytic colitis complicated by a mass in the terminal ileum

Lymphocytic colitis is a chronic inflammatory disease affecting the bowel. The clinical course of lymphocytic colitis is believed to be benign with watery diarrhoea. We report herein what is, to the best of our knowledge, the first case of lymphocytic colitis complicated by a terminal ileal mass. A 23-year-old man presented with diarrhoea. Blind biopsies of samples taken from the terminal ileum, caecum and ascending colon showed features of lymphocytic colitis. He declined treatment with budesonide or 5-aminosalicylates. He presented 14 months later with pain over the right lumbar region and nausea. Computed tomographic enteroclysis showed a focal soft tissue enhancing mass at the terminal ileum. Excision of the soft tissue mass revealed that it was reactive nodular lymphoid hyperplasia with fibrous granulation tissue. In conclusion, an untreated lymphocytic colitis may result in the formation of an inflammatory mass lesion.

Microscopic colitis and colorectal neoplastic lesion rate in chronic nonbloody diarrhea: a prospective, multicenter study

BACKGROUND

Lymphocytic and collagenous colitis are emerging as common findings in subjects undergoing colonoscopy for chronic non-bloody diarrhea (CNBD). Data concerning microscopic colitis (MC) are still limited and affected by controversial epidemiological evidences. Recent converging lines of evidence suggest that MC correlates a lower risk of colorectal neoplasia. Accordingly, we prospectively assessed MC prevalence in a multicenter cohort of subjects submitted to colonoscopy for CNBD, thereby defining whether MC influences the risk of colorectal neoplasia.

METHODS

Consecutive patients with CNBD of unknown origin underwent pan-colonoscopy with multiple biopsies. The prevalence of neoplastic patients in MC was compared with that observed in negative CNBD subjects.

RESULTS

Among 8006 colonoscopy, 305 subjects were enrolled for CNBD. Patients with CNBD were more likely to be women than men (odds ratio = 1.5; P = 0.001). Histopathology detected high prevalence of MC (16%) with a clear predominance of collagenous colitis (70%). A striking age-dependent rise in MC-associated risk was observed, depicting outstanding differences among varying age groups, as in the number needed to screen 1 new case. Gender distribution was balanced within MC patients (Female/Male = 1.5/1), especially among lymphocytic colitis (Female/Male = 1.2/1). MC patients were negatively associated with the risk of neoplastic polyps compared with negative CNBD subjects (odds ratio = 0.22; P = 0.035).

CONCLUSIONS

MC is the first cause of CNBD in subjects submitted to colonoscopy. Multiple biopsies are strongly recommended, even in the case of uneventful endoscopic inspection, especially for age ≥40 years. MC has a reduced risk of colorectal neoplasia, suggesting that this model of chronic inflammation plays a protective effect against colorectal carcinogenesis.

[Eosinophilic and lymphocytic colitis: different histological manifestations of a same process in patients with chronic diarrhea]

OBJECTIVES

1) To determine the prevalence of increased number of eosinophils in colonic mucosa of patients with lymphocytic colitis (LC). 2) To determine the coexistence of eosinophilic colitis (EC) in patients with lymphocytic colitis.

MATERIALS AND METHODS

slides of adult patients with cronic diarrhea with diagnosis of LC were reviewed between October 2009 and March 2012. The number of eosinophils was quantified.

RESULTS

Sixty eight patients with LC were included. Elevated eosinophils were found in 76.5 and in 51.4% a diagnosis of EC was established.

CONCLUSION

3 out of 4 patients with LC had elevated eosinophils and 1 of 2 patients with LC had criteria for EC.

[Microscopic colitis]

Microscopic colitis is characterized by chronic or intermittent watery diarrhoea. Microscopic colitis is a common cause of chronic diarrhoea in predominantly older adults. The underlying mechanism in the pathogenesis of microscopic colitis remains unspecified. Microscopic colitis including colitis collagenous, lymphocytic, microscopic colitis with incomplete findings, minimal change colitis, eosinophilic colitis, Brainerd´s diarrhoea, graft-versus-host disease, mastocytic enterocolitis and postinfectious irritable bowel syndrome. Careful consideration of the clinical features and colonic mucosal biopsies usually lead to correct diagnosis. Treatments of microscopic colitis were based primarily on case reports and personal experience. Many medications have been proposed that either offer symptomatic relief (loperamide, cholestyramine) or had anti-inflammatory or immunosuppressive properties (aminosalicylates, steroids, adalimumab, azathioprine).

The various faces of autoimmune endocrinopathies: non-tumoral hypergastrinemia in a patient with lymphocytic colitis and chronic autoimmune gastritis

Serum gastrin levels exceeding 1000pg/ml (normal, <100) usually raise the suspicion for a neuroendocrine tumor (NET) that secretes gastrin. Rarely, such elevated gastrin levels are seen in patients with pernicious anemia which most commonly is associated with autoimmune gastritis (AG). AG can occur concomitantly with other autoimmune disorders including lymphocytic colitis (LC). Gastrin stimulates enterochromaffin-like cells which increase histamine secretion. Histamine excess can cause diarrhea as can bacterial overgrowth or LC. We present a 57-year-old woman with diarrhea, sporadic epigastric pain, and bloating. She also had a history of interstitial cystitis and took pentosan polysulfate and cetirizine. She had no history of ulcers, renal impairment or carcinoid syndrome. Fasting serum gastrin was 1846pg/ml. Esophagoduodenal gastroscopy and biopsies revealed chronic gastritis and a pH of 7 with low stomach acid. Serum gastrin and plasma chromogranin A were suggestive of a gastrinoma or NET. Pernicious anemia was unlikely. Imaging studies did not reveal any tumor. Random colonic biopsy was compatible with LC, possibly explaining her diarrhea, although we also considered excessive histamine from elevated gastrin, bacterial overgrowth, and pentosan polysulfate which can cause diarrhea and be misleading in this setting, pointing to the diagnosis of gastrinoma. At 4year follow-up in 2012, fasting serum gastrin was 1097pg/ml and the patient asymptomatic taking only cetirizine for nasal allergies. This case illustrates that diarrhea may be associated with very high serum gastrin levels in the setting of chronic gastritis, LC, and interstitial cystitis (pentosan use), without clear evidence for a gastrinoma or NET. If no history of ulcers or liver metastases is present in such cases, watchful observation rather than an extensive/invasive and costly search for a NET may be justified. Considering the various forms of polyglandular syndrome, this may represent a variant and we here provide an algorithm for working up such patients, while also reviewing literature on the intertwined relationship between the immune and endocrine systems.

Non-IBD colitides (eosinophilic, microscopic)

Microscopic colitis includes the terms lymphocytic colitis and collagenous colitis, and is a common cause of chronic diarrhoea in older adults. The incidence of microscopic colitis has increased over time and has reached levels comparable to other forms of inflammatory bowel disease. In this chapter, an updated review on the epidemiology, diagnosis and treatment of microscopic colitis has been provided. There is limited data available about eosinophilic colitis, which is the least common of the eosinophilic GI disorders. It is important to rule out the secondary causes of colonic eosinophilia in patients with suspected eosinophilic colitis.

Clinical course of microscopic colitis in a single-center cohort study

BACKGROUND AND AIMS

The long-term natural history of collagenous (CC) and lymphocytic colitis (LC) is not well known. The aims of this study were to evaluate the clinical course of microscopic colitis (MC) and to describe the morbidity evolution of the disease.

MATERIAL AND METHODS

This study is based on a cohort of 54 patients (35 LC/19 CC), previously included in a randomized trial treated with mesalazine with or without cholestyramine. Patients were followed-up closely during the subsequent 5 years, undergoing clinical, endoscopic and histologic evaluation at least yearly. After this period, they were encouraged to undergo periodical clinical evaluations.

RESULTS

In a mean follow-up time of 104.9 ± 14.1 months (range 81-138 months) at the end of the therapy, 12 patients (7 LC and 5 CC) relapsed. Of these patients, 4 reported a mild clinical relapse self-treated with antidiarrheal medication. In total 49 patients are clinically free from diarrhea, to date. At multivariate analysis the only predictive factor of relapse seems to be a slow response to treatment.

CONCLUSIONS

Only a minority of patients with MC had diarrhea more than once a week in a long-term follow-up and the symptom pattern was similar between CC and LC patients.

Lansoprazole-induced microscopic colitis: an increasing problem? Results of a prospecive case-series and systematic review of the literature

BACKGROUND

Microscopic colitis (MC), comprising lymphocytic and collagenous colitis (LC, CC), causes chronic diarrhoea. Lansoprazole can cause MC. Likelihood criteria defining the causative relationship between drugs and MC have not been applied to lansoprazole, nor has lansoprazole-related-MC been characterized.

AIM

To analyse a series of lansoprazole-related MC cases, and characterize lansoprazole-related CC and LC.

METHODS

Cases were diagnosed over 23 months and causal relationship evaluated by established likelihood criteria. A systematic Medline search was conducted and publications analysed.

RESULTS

Eight patients had lansoprazole-related MC. In all cases chronological and causality likelihood scores supported lansoprazole causative role. Discontinuation determined resolution without further treatment. Twenty-five cases of lansoprazole-related MC from 10 publications were grouped with the present series, and differences between CC and LC analysed. CC cases had more macroscopic alterations at colonoscopy (72.2 vs. 6.6%; p=0.0002). Time between lansoprazole start and symptoms onset was longer for CC (median 60 vs. 28 days; p=0.03).

CONCLUSIONS

Peculiar features of lansoprazole-related CC were described through the analysis of a newly diagnosed lansoprazole-related MC series in which the causative role of lansoprazole was for the first time defined by established likelihood criteria, and by pooled evaluation with other cases retrieved by a systematic literature review.

Seizures in an Alzheimer's disease patient as a complication of colonoscopy premedication with meperidine

We describe the first reported case of generalized tonic-clonic seizures induced by meperidine premedication for a colonoscopy procedure in a 63-year-old woman with Alzheimer's disease. The active metabolite of meperidine, normeperidine, is postulated to be the precipitating cause of the seizures, although a cholinesterase inhibitor and an N-methyl-D: -aspartate receptor antagonist, both routinely used for treatment of Alzheimer's disease, may have contributed by reducing the seizure threshold. The neuronal changes which occur in Alzheimer's disease can themselves also predispose to seizures. We recommend avoidance of meperidine for all flexible endoscopic procedures on patients with Alzheimer's disease and in any patient with a condition that predisposes to seizures, and suggest the use of alternative opioids.

Mechanism of diarrhea in microscopic colitis

AIM: To search the pathophysiological mechanism of diarrhea based on daily stool weights, fecal electrolytes, osmotic gap and pH.

METHODS: Seventy-six patients were included: 51 with microscopic colitis (MC) [40 with lymphocytic colitis (LC); 11 with collagenous colitis (CC)]; 7 with MC without diarrhea and 18 as a control group (CG). They collected stool for 3 d. Sodium and potassium concentration were determined by flame photometry and chloride concentration by titration method of Schales. Fecal osmotic gap was calculated from the difference of osmolarity of fecal fluid and double sum of sodium and potassium concentration.

RESULTS: Fecal fluid sodium concentration was significantly increased in LC 58.11±5.38 mmol/L (P<0.01) and CC 54.14±8.42 mmol/L (P<0.05) than in CG 34.28±2.98 mmol/L. Potassium concentration in LC 74.65±5.29 mmol/L (P<0.01) and CC 75.53±8.78 mmol/L (P<0.05) was significantly less compared to CG 92.67±2.99 mmol/L. Chloride concentration in CC 36.07±7.29 mmol/L was significantly higher than in CG 24.11±2.05 mmol/L (P<0.05). Forty-four (86.7%) patients had a secretory diarrhea compared to fecal osmotic gap. Seven (13.3%) patients had osmotic diarrhea.

CONCLUSION: Diarrhea in MC mostly belongs to the secretory type. The major pathophysiological mechanism in LC could be explained by a decrease of active sodium absorption. In CC, decreased Cl/HCO₃ exchange rate and increased chloride secretion are coexistent pathways.

[Microscopic colitis--more common cause of diarrhea than believed. Biopsies are the only way to diagnosis, drug treatment is effective]

Microscopic colitis, encompassing collagenous and lymphocytic colitis, is a fairly common cause of chronic watery diarrhoea, especially in elderly women. In recent epidemiological studies the annual incidence of each disorder was 4-6/100.000 inhabitants. The aetiology is unknown. The main clinical symptoms are watery diarrhoea, weight loss and abdominal pain. Laboratory analyses are nondiagnostic, and the diagnoses rely on histopathological examination of colonic mucosal biopsies. There is an association to autoimmune diseases such as thyroid disorders, diabetes mellitus, celiac disease and arthritis. Budesonide is the best-documented treatment of collagenous colitis. It is superior to placebo in short-term therapy, but the long-term efficacy is not well studied. The evidence for other therapeutic alternatives such as loperamide, cholestyramine, bismuth subsalicylate, or 5-aminosalicylates is weak. In unresponsive severe disease azathioprine or methotrexate may be tried. There are at present no controlled data on the treatment of lymphocytic colitis. The long-term prognosis of microscopic colitis is good, serious complications are rare and there is no increased mortality.

Microscopic colitis: a report of two cases

Microscopic colitis is characterized by chronic, watery, secretory diarrhea, with a normal or near-normal gross appearance of the colonic mucosa. Biopsy is diagnostic and usually reveals either lymphocytic colitis or collagenous colitis. The symptoms of collagenous colitis appear most commonly in the sixth decade. With collagenous colitis, the major microscopic characteristic is a thickened collagen layer beneath the colonic mucosa, and with lymphocytic colitis, an increase number of intraepithelial lymphocytes. Clinically, collagenous colitis is characterized by long-standing diarrhea. In patients with lymphocytic colitis, the duration of diarrhea is usually shorter and female predominance is less apparent. We report two cases of lymphocytic colitis in elderly women. Both presented with watery diarrhea of two month duration and weight loss. Extensive investigations were done and several medications failed to stop their diarrhea. Biopsy revealed lymphocytic colitis. Their diarrhea responded well to cholestyramine.