Usefulness of ultrasonographic evaluation of stool and/or gas distribution for the treatment strategy of chronic constipation

The Effectiveness of Transabdominal Ultrasonography in Managing Chronic Constipation in the Elderly, with a Focus on the Underlying Pathological Conditions

Chronic constipation is more common in the elderly and associated with numerous diseases. For the diagnosis of chronic constipation in the elderly, it is essential to exclude constipation secondary to colorectal cancer or other causes. Chronic constipation in the elderly also often requires lifestyle modifications, as well as drug treatments because of the involvement of pathologies such as reduced colonic transport capacity and rectal hyposensitivity. Therefore, it is extremely important to evaluate the pathophysiology of both the colon and the rectum. Transabdominal ultrasonography (TUS) is a key technique for providing comprehensive medical care and allows simultaneous functional assessment and exclusion of organic diseases related to constipation such as colorectal cancer. Although several studies have reported the clinical utility of TUS for chronic constipation, which includes its simplicity, noninvasiveness, and low cost, the majority were in children. Thus, there are limited studies in adults. Herein, we review the utility of TUS for indirect assessment of colonic transit time using several TUS parameters that can be applied clinically, as well as treatment options for chronic constipation. The constipation index (i.e., mean transverse diameter of the colon), assessed by TUS, is a useful indirect indicator of colonic transit time. If the constipation index is <21.2, increased fiber or treatment with osmotic agents should be used. If the constipation index is ≥21.2, then the ratio of the left to the right lateral colonic diameters should be evaluated. If this value is ≥0.5, a secretagogue or bile acid transporter inhibitor should be administered. It is noteworthy that nursing care is becoming increasingly important in Japan's super-aging society. A significant proportion of nursing care is provided to patients with chronic constipation, a cohort that is predicted to grow in the future. In these patients, fecal masses often remain in the rectum, which may require an enema or stool extraction. Therefore, it is important to assess both the presence of feces in the rectum and the consistency of the feces. Recently, portable ultrasound (US) devices equipped with artificial intelligence have been developed and used clinically for treatment of patients with chronic constipation in nursing care. Rectal findings using portable US devices can aid in selecting appropriate constipation treatments. Thus, portable US will likely become increasingly important as a next-generation examination device in nursing care. TUS (including portable US) is noninvasive, simple, and repeatable and will become a fundamental modality in the management of chronic constipation.

Evidence-Based Clinical Guidelines for Chronic Constipation 2023

The Japan Gastroenterological Association published the first version of its clinical guidelines for chronic constipation 2023. Based on the latest evidence, these guidelines describe the definition, classification, diagnostic criteria, diagnostic testing methods, epidemiology, pathophysiology, and treatment of chronic constipation. They include flowcharts for both diagnosis and treatment of chronic constipation. In the treatment of chronic constipation, the first step involves differentiating between secondary forms, such as organic disease-associated constipation, systemic disease-associated constipation, and drug-induced constipation. The next step is to determine whether the chronic constipation stems from a motility disorder, a form of primary chronic constipation. For functional constipation and constipation-predominant irritable bowel syndrome, treatment should be initiated after evaluating symptoms like reduced bowel movement frequency type or defecation difficulty type. The first line of treatment includes the improvement of lifestyle habits and diet therapy. The first drugs to consider for oral treatment are osmotic laxatives. If these are ineffective, secretagogues and ileal bile acid transporter inhibitors are candidates. However, stimulant laxatives are exclusively designated for as-needed use. Probiotics, bulk-forming laxatives, prokinetics, and Kampo medicines, for which there is insufficient evidence, are considered alternative or complementary therapy. Providing the best clinical strategies for chronic constipation therapy in Japan, these clinical guidelines for chronic constipation 2023 should prove useful for its treatment worldwide. The Japan Gastroenterological Association published the first version of its clinical guidelines for chronic constipation 2023. Based on the latest evidence, these guidelines describe the definition, classification, diagnostic criteria, diagnostic testing methods, epidemiology, pathophysiology, and treatment of chronic constipation. They include flowcharts for both diagnosis and treatment of chronic constipation. In the treatment of chronic constipation, the first step involves differentiating between secondary forms, such as organic disease-associated constipation, systemic disease-associated constipation, and drug-induced constipation. The next step is to determine whether the chronic constipation stems from a motility disorder, a form of primary chronic constipation. For functional constipation and constipation-predominant irritable bowel syndrome, treatment should be initiated after evaluating symptoms like reduced bowel movement frequency type or defecation difficulty type. The first line of treatment includes the improvement of lifestyle habits and diet therapy. The first drugs to consider for oral treatment are osmotic laxatives. If these are ineffective, secretagogues and ileal bile acid transporter inhibitors are candidates. However, stimulant laxatives are exclusively designated for as-needed use. Probiotics, bulk-forming laxatives, prokinetics, and Kampo medicines, for which there is insufficient evidence, are considered alternative or complementary therapy. Providing the best clinical strategies for chronic constipation therapy in Japan, these clinical guidelines for chronic constipation 2023 should prove useful for its treatment worldwide.

A Handheld Ultrasound Device Can Predict Constipation with Rectal Fecal Retention in a Palliative Care Setting

Although handheld ultrasound devices (HUDs) are commonplace, their ability to diagnose fecal retention (FR) remains unclear. This prospective observational study examined HUDs' usefulness in diagnosing FR in patients with constipation in a palliative care setting. Between 10 December 2020 and 30 June 2022, we compared rectal ultrasonographic findings obtained using HUDs with clinical manifestations in 64 males and 70 females (48%, 52%, 68 ± 11 years old) with constipation who had undergone computed tomography (CT). FR was diagnosed using a HUD and compared with CT and digital rectal examination (DRE) results. In total, 42 (31%), 42 (31%), and 41 (31%) patients were diagnosed using HUDs, CT, and DRE, respectively. Thirty-nine (93%) patients in the CT group were also diagnosed with FR using HUDs. A total of 89 of 92 patients with a negative CT diagnosis also had a negative HUD diagnosis. Among the 41 patients in the DRE group, 37 were also diagnosed with FR using HUDs. Among 93 patients with a negative DRE diagnosis, 86 had a negative HUD diagnosis. The sensitivity, specificity, positive predictive value, and negative predictive value of HUDs for CT were 93%, 97%, 93%, and 97%, respectively. Those of HUDs for DRE were 88%, 94%, 86%, and 95%, respectively. The concordance rates for FR diagnosis were 128/134 for CT and HUDs and 123/134 for DRE and HUDs. HUD was useful for diagnosing FR in this setting. HUDs could provide valuable support for appropriate treatment selection. Developing a constipation treatment algorithm based on rectal ultrasonographic findings is warranted in the future.

Evaluating Accuracy of Rectal Fecal Stool Assessment Using Transgluteal Cleft Approach Ultrasonography

BACKGROUND

Transabdominal ultrasound is used to detect fecal impaction, but the rectum is difficult to visualize without bladder urine or with gastrointestinal gas.

OBJECTIVE

We developed a transgluteal cleft approach that is unaffected by these factors and sought to determine if our ultrasound method could detect and classify fecal matter in the lower rectum using this approach.

METHODS

We classified ultrasound images from hospitalized patients into four groups: Group 1 (bowed and rock-like echogenic areas), Group 2 (irregular and cotton candy-like hyperechoic areas), Group 3 (flat and mousse-like hyperechoic areas), and Group 4 (linear echogenic areas in the lumen). Stool characteristics were classified as hard, normal, and muddy/watery. Sensitivity and specificity were determined based on fecal impaction and stool classification accuracy.

RESULTS

We obtained 129 ultrasound images of 23 patients. The sensitivity and specificity for fecal retention in the rectum were both 100.0%. The recall rates were 71.8% for Group 1, 93.1% for Group 2, 100.0% for Group 3, and 100.0% for Group 4. The precision rates were 96.6% for Group 1, 71.1% for Group 2, 88.9% for Group 3, and 100.0% for Group 4. Our method was 89.9% accurate overall.

CONCLUSION

Transgluteal cleft approach ultrasound scanning can detect and classify fecal properties with high accuracy.

Diagnostic Ability of Ultrasonography Compared with Computed Tomography for Assessing Rectal Feces

Objectives

Chronic constipation is a common gastrointestinal disorder, and management is crucial. Computed tomography (CT) is useful for evaluating rectal fecal mass but limited owing to radiation exposure, cost, and inaccessibility at certain facilities. Ultrasonography (US) avoids these pitfalls, but it is unknown whether it accurately assesses rectal feces. In this study, we evaluated the diagnostic performance of US compared with CT as the gold standard for assessing rectal feces.

Methods

We prospectively evaluated rectal fecal mass retention using US performed within 1 h of CT to assess the degree of agreement between methodologies. Rectal stool findings were evaluated on three levels: no stool (R1), presence of stool (R2), and hard stool filling (R3).

Results

The sample included 100 patients (55 men, 45 women), of whom 47 were constipated. The kappa coefficients for rectal content detection were excellent between US and CT (p <0.001). Eighty-two cases (R1: 46 cases; R2: 28 cases; R3: 8 cases) were matched with CT and US findings, and 18 were not. Cases that did not match had low urine or high gas volumes. CT and US findings showed high agreement in constipation (kappa coefficient 0.674, p <0.001) and non-constipation groups (kappa coefficient 0.677, p <0.001). All cases with R3 on CT were found in the constipation group, while more than half of the cases with R1 on CT were in the non-constipation group.

Conclusions

CT and US showed high agreement in evaluating rectal fecal mass retention, indicating that US can substitute CT.

Current Treatment Practices for Adult Patients with Constipation in Japan

BACKGROUND

The prevalence of constipation in Japan is estimated to be 2-5%. Constipation is a disease found in older adults. In particular, Japan is an aging society, with 65% of men and 80.5% of women aged 65 years or older accounting for the majority of its population. Chronic constipation may be associated with survival, cardiovascular events, decreased quality of life, and death. This study summarizes the recent findings regarding constipation treatment practice in Japan.

SUMMARY

Until recently, the diagnosis of constipation was mainly based on medical interviews; however, with the recent development of handheld ultrasound devices, both physicians and nurses can easily and objectively diagnose fecal retention. Magnesium oxide and stimulant laxatives have been the mainstay treatments; however, since 2012, more than five new drugs for treating constipation have become available in Japan.

KEY MESSAGES

Magnesium oxide is less effective in patients who use acid-secretion inhibitors and patients who have undergone total gastrectomy and should be cared for hypermagnesemia. In addition, regular use of stimulant laxatives may lead to colonic inertia and decreased bowel movements; therefore, they should be used only occasionally. The following is an overview of the different uses of conventional and newer laxatives for treating constipation.

Expert Consensus Document: Diagnosis for Chronic Constipation with Faecal Retention in the Rectum Using Ultrasonography

Chronic constipation is a common gastrointestinal disorder in older adults, and it is very important to manage chronic constipation. However, evaluating these subjective symptoms is extremely difficult in cases where patients are unable to express their symptoms because of a cognitive or physical impairment. Hence, it is necessary to observe the patient's colonic faecal retention using objective methods. Ultrasonography observation for colonic faecal retention is useful for diagnosing constipation and evaluating the effectiveness of treatment. Since there was no standard protocol for interpreting rectal ultrasonography findings, we developed an observation protocol through an expert consensus. We convened a group of experts in the diagnosis and evaluation of chronic constipation and ultrasonography to discuss and review the current literature on this matter. Together, they composed a succinct, evidence-based observation protocol for rectal faecal retention using ultrasonography. We created an observation protocol to enhance the quality and accuracy of diagnosis of chronic constipation, especially rectal constipation. This consensus statement is intended to serve as a guide for physicians, laboratory technicians and nurses who do not specialise in ultrasound or the diagnosis of chronic constipation.