Priyadarshini Loganathan, MD1, Babu P. Mohan, MD, MS2, Douglas G. Adler, MD, FACG3 1University Health San Antonio, San Antonio, TX; 2University of Utah School of Medicine, Salt Lake City, UT; 3Centura Health-Porter Adventist Hospital, Salt Lake City, UT
Introduction: Chronic diarrhea is a frequently encountered indication for outpatient colonoscopy. Majority of the colonoscopic exams in stable chronic diarrhea patients do not reveal endoscopic abnormalities. Although normal appearing, routine random colon biopsies are taken for further diagnostic assessment. No previous meta-analysis exists assessing the diagnostic yield of histopathological analysis in chronic diarrhea patients with a normal colonoscopy exam. In this study, we aim to perform a systematic review and meta-analysis to study the diagnostic value of random colon biopsies in these patients.
Methods: Multiple databases, including Medline, Scopus, and Embase, were searched from inception to May 2022 using specific terms for studies evaluating the diagnostic yield of random biopsies in chronic diarrhea patients with normal colonoscopy exams. Outcomes of interest were the diagnostic yield of microscopic colitis, inflammatory bowel disease, significant histopathologic disease, and normal biopsy. Standard meta-analysis methods were employed using the random-effects model, and heterogeneity was assessed using the I2 statistics.
Results: Initial database search yielded 1459 articles, of which 22 studies were finally included. Total of 3935 patients (48.9% females) with mean age of 42.32 years were included in the final analysis. The pooled rate of normal colon biopsy was 49.8% (95% CI 34.3-65,2, I2=98%) and normal ileal biopsy was 88.5% (51.3-98.3, 93%). The pooled rate of specific diagnosis based on random colonic biopsy were as follows: microscopic colitis 15.1% (95% CI 10.8-20.7, I2=91%), lymphocytic colitis 9.3% (6.6-13, I2= 83%) collagenous colitis 3.7% (2.4-5.7, I2= 79%), nonspecific colitis 19.7% (11-32.8, I2= 97%), inflammatory bowel disease 1.7% (0.8-3.5, I2= 54%), infective colitis 2% (1.1-3.7, I2=17%), and eosinophilic colitis 2.3% (1.1-4.5, I2= 69%) as shown in Table 1. The pooled rate of total significant histopathological change was 32.9% (23.8-43.5, I2= 96%).
Discussion: Based on meta-analysis of 22 studies, normal colon biopsy was observed in 49.8% and normal ileum biopsy was observed in 88.5%. Pooled rate of microscopic colitis was 15.1% and total significant histopathological change was noted in 32.9%. Our study adds important data to the current clinical care of patients with chronic diarrhea who undergo colonoscopy exam with random biopsies.
Outcome:
Diagnostic value of random colonic biopsy in the evaluation of chronic unexplained diarrhea with normal colonic appearance.
Pooled rate
95% confidence interval,
(I2% heterogeneity)
Number of studies
Normal colon biopsy
49.8%
34.3-65.2, (98%)
18 studies
Normal ileum biopsy
88.5%
51.3-98.3, (93%)
3 studies
Microscopic colitis
15.1%
10.8-20.7, (91%)
19 studies
Lymphocytic colitis
9.3%
6.6-13, (83%)
15 studies
Collagenous colitis
3.7%
2.4-5.7, (79%)
13 studies
Nonspecific colitis
19.7%
11-32.8, (97%)
14 studies
Inflammatory bowel disease
1.7%
0.8-3.5, (54%)
12 studies
Infective colitis
2%
1.1-3.7, (17%)
8 studies
Eosinophilic colitis
2.3%
1.1-4.5, (69%)
11 studies
Total significant histopathological change
32.9%
23.8-43.5, (96%)
22 studies
Table: Table 1: Summary of pooled rates
Disclosures:
Priyadarshini Loganathan indicated no relevant financial relationships.
Babu Mohan indicated no relevant financial relationships.
Douglas Adler: Boston Scientific – Consultant.
Priyadarshini Loganathan, MD1, Babu P. Mohan, MD, MS2, Douglas G. Adler, MD, FACG3. E0101 - Diagnostic Yield of Random Colon Biopsy in Chronic Diarrhea Patients With Normal Colonoscopy: A Systematic Review and Meta-Analysis, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.
