Development of a Score to Predict Positive Colonic Histology in Chronic Diarrhea Assessed in Open-access Colonoscopy

Area of Science:

• Gastroenterology
• Diagnostic Yield
• Histopathology

Background:

• Chronic diarrhea evaluation often includes colonoscopy and esophagogastroduodenoscopy.
• Initial work-up for chronic diarrhea can be inconclusive, necessitating further endoscopic investigation.

Purpose of the Study:

• To determine the diagnostic yield of colonoscopy and esophagogastroduodenoscopy with biopsies in chronic diarrhea.
• To identify predictors of positive colonic histology in this patient group.

Main Methods:

• Retrospective review of 1022 patients with chronic diarrhea undergoing initial colonoscopy.
• Logistic regression analysis to identify predictors of positive colonic histology.
• Development and validation of a clinical diagnostic scoring system.

Main Results:

• Positive colonic histology was found in 13.3% of patients with endoscopically normal colons, primarily microscopic colitis.
• Ileal and duodenal biopsies yielded diagnoses in 4% and 5% of cases, respectively.
• Older age predicted positive histology, while higher BMI and longer diarrhea duration predicted negative histology. A clinical score predicted normal histology in 41-54% of patients.

Conclusions:

• Colonoscopy with biopsies has a low yield for diagnosing chronic diarrhea when the colon appears normal.
• A clinical scoring system can help predict the likelihood of normal colonic histology, potentially guiding further diagnostic strategies.