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).
Age
18–any
Sex
ALL
Healthy volunteers
Not accepted
You may be eligible if
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.
