Symptomatic Microscopic Colitis Atop Quiescent Inflammatory Bowel Disease: A Case Series.

Microscopic colitis (MC) has rarely been described to be the cause of watery diarrhea in those with established inflammatory bowel disease (IBD), and instead has been presented as a herald syndrome to eventual IBD or incidentally found in asymptomatic IBD patients. We report a case series of 7 patients with IBD who presented with a watery diarrheal exacerbation due to new-onset MC. We propose that new-onset MC should be considered in the differential diagnosis of watery diarrhea occurring in patients with long-standing IBD and that evaluation should include colonoscopy with biopsies obtained throughout the colon.