Overview
This is an open label study looking at rifaximin therapy for the treatment of microscopic (collagenous or lymphocytic) colitis.
Description
This is an open-label single-arm trial to evaluate the efficacy of Rifaximin in patients with active microscopic colitis (MC). 10 subjects will be asked to take 500mg Rifaximin three times per day for 4 weeks. The primary endpoints will be histologic response and clinical remission (less than 3 stools per day and less than 1 watery stool per day within the prior 7 days. The secondary endpoint will be change of the MC Disease Activity Index (MCDAI).
Eligibility
Inclusion Criteria:
- Collagenous colitis (CC) or lymphocytic colitis (LC) diagnosed on colon biopsies reviewed by 2 separate pathologists
- CC will be defined histologically to be the following: thickness of the collagenous subepithelial table >10 micrometer using an ocular micrometer, inflammation in the lamina propria consisting of mainly lymphocytes and plasma cells, lack of crypt architectural distortion, and regenerative-appearing changes in the surface and/or crypt epithelium
- LC will be defined histologically to be the following: intraepithelial lymphocytes >20 per 100 epithelial cells in the subjective area of highest lymphocyte density, inflammation in the lamina propria consisting of mainly lymphocytes and plasma cells, and regenerative-appearing changes in the surface and/or crypt epithelium
- Subjects in active flare, defined as >3 watery/loose stools per day on >4 / 7 days over >4 weeks in the past 3 months.
Exclusion Criteria:
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