Through adequate sampling, careful histopathological examination of biopsies and close collaboration between gastroenterologists, endoscopists and pathologists, it is very possible to make an accurate diagnosis to provide the most effective therapy for patients with noninflammatory bowel disease (non-IBD) colitis, Anita Afzali, MD, said during the postgraduate course presentation at the 2023 ACG Annual Scientific Meeting and Postgraduate Course in Vancouver, Canada.

Dr Afzali is a professor of medicine in the division of digestive diseases and executive vice chair of department of medicine at the University of Cincinnati in Cincinnati, Ohio.

“Discrimination between IBD versus non-IBD mimickers may include, but not be limited to, history and symptoms, location of disease, endoscopic appearance, histologic appearance and radiographic appearance,” Dr Afzali explained.

Microscopic colitis, with its 2 subtypes, collagenous colitis and lymphocytic colitis, presents with intermittent watery diarrhea, abdomenal pain, arthralgia, and mild body weight loss—all symptoms that often make it indistinguishable from irritable bowel syndrome .

So how does the gastroenterologist distinguish microscopic colitis from IBD? Microscopic colitis usually presents in older population, Dr Afzali explained. “Watery diarrhea but no blood, no ulcers in endoscopy, no chronicity on histopathology, and normal imaging are the typical markers to help separate one from the other,” she said.

Segmental colitis associated with diverticulosis (SCAD), while like IBD in terms of endoscopic and histologic findings, is generally typical among older patients. “SCAD spares the rectum, has a lower relapse rate, and usually manifests without fever,” Dr Afzali said.

NSAID colopathy, on the other hand, has so many clinical overlaps with IBD that it is challenging to distinguish between the 2 conditions. “Consulting a pathologist and checking for mucosal inflammation between ulcers could help,” Dr Afzali said. Withdrawing from NSAIDs could be the resolution to the problem, she said.

For diversion colitis, it would be difficult to distinguish from IBD “especially if the patient also has IBD.” Looking into barotrauma bleeding and clinical history could help, along with instilling stoma content in diverted colonic segment, she added.

Differentiating radiation proctitis from IBD may include history, endoscopic appearance, and histology. “Treating the condition with sucralfate enemas, mesalamine, endoscopic therapy, hyperbaric oxygen, and surgery would be good markers,” Dr Afzali concluded.

Reference:
Afzali A. The non-IBD colitis: Microscopic, indeterminant, and diverticular disease-associated colitis. Session 1A: It’s all about inflammation. Presented at: 2023 ACG Postgraduate Course. Vancouver, Canada. October 21, 2023.