Ultrasonographic evaluation of changes over time in one defecation cycle in adults with functional constipation: A report of two cases

Meta-analysis: Intestinal ultrasound to evaluate colonic contents and constipation

BACKGROUND

Constipation can be diagnosed clinically using the Rome criteria. Ultrasound (US), which lacks the radiation exposure of conventional X-ray, holds promise as a non-invasive tool to evaluate colonic contents and constipation.

AIM

To examine the role of US in the assessment of constipation.

METHODS

We performed a systematic search of Embase (OVID, 1984), Medline (Ovid, 1946), Cochrane Central, ClinicalTrials.gov and Australia New Zealand Clinical Trials Registry from database inception to 26 January 2024 according to PRISMA guidelines and prospectively registered with PROSPERO. All studies using US to assess constipation or colonic contents in either adults or children were included. Rectal diameter measurements were pooled in meta-analysis. Risk of bias was assessed using the Newcastle Ottawa Scales and Joanna Briggs Institute checklists.

RESULTS

Of 12,232 studies screened, 51 articles (6084 patients; 3422 children) describing US to assess symptoms in patients with constipation were included. Most studies used Rome criteria to diagnose constipation. Rectal diameter was associated with clinical constipation in 29 paediatric studies (3331 patients). Meta-analysis showed the mean rectal diameter of constipated patients was significantly higher than controls (mean difference 12 mm, 95% confidence intervals (CI): 6.48, 17.93, p < 0.0001, n = 16 studies). Other features of constipation on US included posterior acoustic shadowing and echogenicity of luminal contents.

CONCLUSION

US is an appealing imaging modality to assess luminal contents and constipation. Further well-designed studies are required to validate US metrics that accurately identify constipation.

Development of colonic transit time and ultrasound imaging tools as objective indicators for assessing abnormal defecation associated with food intake: a narrative review based on previous scientific knowledge

Background

Functional gastrointestinal disorders (FGIDs) involve chronic or persistent gastrointestinal symptoms. Laboratory tests show no organic lesions, and the symptoms are due to dysfunction. The most typical FGID is irritable bowel syndrome (IBS). In IBS patients, defecation disorders are common and have adverse effects on daily life. The proper evaluation and analysis of colonic transit are important for the management of defecation disorders in IBS patients. In addition, dietary intake and lifestyle affect colonic transit. An accurate assessment of such factors can guide management, leading to improvements in colonic transit and the resolution of defecation disorders.

Main topic

The Rome IV diagnostic criteria for IBS are based on subjective symptoms, which must be communicated and explained by the patient, limiting their application. Colonic transit time and ultrasonography are objective tools that can be used to diagnose IBS. In particular, previous studies used colonic transit to accurately distinguish between constipation and normal stool passage and to assess delayed gastrointestinal motility. Diet and lifestyle modifications can improve colonic transit and ameliorate bowel dysfunction.

Conclusion

Colonic transit can be improved by modifying lifestyle factors. Defecation disorders in IBS patients may be resolved by focusing on such factors. In the future, methods of visualizing defecation disorders due to impaired gastrointestinal motility and objective indicators of the associated abdominal symptoms need to be investigated.

Can irritable bowel syndrome be detected by ultrasound?

Functional gastrointestinal disease is one in which gastrointestinal symptoms persist chronically or recurrently. This disease is challenging because it does not have an organic cause that can be detected in routine laboratory tests. Among them, the symptoms of irritable bowel syndrome (IBS), which is a type of functional gastrointestinal tract disease, include abnormal bowel movements associated with abdominal pain. However, no specific test has been established to definitively diagnose these diseases, including IBS. The traditional Rome IV diagnostic criteria are used to diagnose IBS by assessing subjective symptoms. However, it has been suggested that IBS is difficult to diagnose using the Rome IV criteria among unconscious or cognitively impaired patients. It is recommended that abdominal ultrasonography be used to assess IBS with diarrhea and constipation. Previously, constipation among elderly people who ingested food orally was objectively assessed by ultrasound, and colonic fecal distribution patterns were classified in constipated patients and healthy people. Objective visualization of the large intestine was used to assess constipation. Therefore, fecal retention among adults and elderly individuals was reported using ultrasonography. It was suggested that stool retention could be confirmed by observing the hyperechoic region of the rectum. Strong hyperechoic regions with acoustic shadows in the rectum indicate the presence of hard stools, thus enabling medical workers to identify constipation. In the future, ultrasonography may be useful for diagnosing IBS in unconscious patients or those with cognitive decline.

Deep learning-based classification of rectal fecal retention and analysis of fecal properties using ultrasound images in older adult patients

AIM

The present study aimed to analyze the use of machine learning in ultrasound (US)-based fecal retention assessment.

METHODS

The accuracy of deep learning techniques and conventional US methods for the evaluation of fecal properties was compared. The presence or absence of rectal feces was analyzed in 42 patients. Eleven patients without rectal fecal retention on US images were excluded from the analysis; thus, fecal properties were analyzed in 31 patients. Deep learning was used to classify the transverse US images into three types: absence of feces, hyperechoic area, and strong hyperechoic area in the rectum.

RESULTS

Of the 42 patients, 31 tested positive for the presence of rectal feces, zero were false positive, zero were false negative, and 11 were negative, indicating a sensitivity of 100% and a specificity of 100% for the detection of rectal feces in the rectum. Of the 31 positive patients, 14 had hard stools and 17 had other types. Hard stool was detected by US findings in 100% of the patients (14/14), whereas deep learning-based classification detected hard stool in 85.7% of the patients (12/14). Other stool types were detected by US findings in 88.2% of the patients (15/17), while deep learning-based classification also detected other stool types in 88.2% of the patients (15/17).

CONCLUSIONS

The results showed that US findings and deep learning-based classification can detect rectal fecal retention in older adult patients and distinguish between the types of fecal retention.

Improvement of Constipation Symptoms in an Older Adult Patient by Defecation Care Based on Using a Handheld Ultrasound Device in Home Care Settings: A Case Report

BACKGROUND

Although previous studies have demonstrated the ability of ultrasound to detect stool in the colon and rectum, the clinical utility of evaluating constipation via ultrasonic imaging by nurses has not been determined. In this case report, we observed fecal retention, assessed the presence of constipation, and performed defecation care in an older adult patient in a home care setting in a city near the metropolitan area in Japan.

CASE

An 85-year-old male with advanced stage prostate cancer and multiple metastases was diagnosed with fecal impaction via digital rectal examination and evaluation of stool consistency. He was managed by regular digital evacuation of stool, but ultrasonic imaging indicated constipation with fecal retention in both the rectum and the colon despite this bowel evacuation program. When faced with this situation, we advocate a bowel management program that considers both intestinal elimination dysfunction and fecal transport dysfunction. Based on ultrasonic imaging, stool consistency was altered by promoting water intake, and we promoted self-defecation by asking the patient to attempt to move his bowels (regardless of cues to defecation) by sitting on the toilet every morning. As a result, the number of weekly enemas and digital dis-impaction episodes decreased while the number of spontaneous defecations increased.

CONCLUSION

This case report demonstrated that ultrasonography improved bowel management in this patient with clinically severe chronic constipation.

Safety and efficacy of a defecation care algorithm based on ultrasonographic bowel observation in Japanese home-care settings: a single-case, multiple-baseline study

AIM

To verify the efficacy of defecation care based on handheld ultrasonographic observations for functional constipation by visiting nurses skilled in bowel ultrasonography.

METHODS

Home-care patients with suspected functional constipation receiving nursing visits were recruited in this multiple-baseline, single-case experiment with intervention points shifted by 1 week. A total of 15 older adults were categorized into 3-, 4-, 5- or 6-week intervention phases. Ultrasonographic observations of fecal retention in the colorectum and defecation care based on observations during the ordinal physical assessment were reviewed. Tau-U was used for confirming the efficacy of the intervention by measuring the number of non-artificial and artificial defecations, as well as hard stools per week, and the amount of non-stimulant and stimulant laxatives, enemas and suppositories per week. For evaluating safety, adverse events, such as bowel obstruction and incontinence-associated dermatitis, were confirmed.

RESULTS

No adverse events were observed. Statistical analysis showed that hard stools and artificial defecation reduced, and that their effect sizes were significant (Tau = -0.48, P < 0.01; Tau = -0.53, P < 0.01). Even the amounts of stimulant laxative and glycerin enema reduced, and their effect sizes were significant (Tau = -0.56, P < 0.01; Tau = -0.34, P = 0.04).

CONCLUSIONS

Thus, defecation care based on ultrasonographic assessment by nurses in home-care settings is safe and effective for improving constipation symptoms and reducing laxative use. Geriatr Gerontol Int 2020; ••: ••-••.