Drug consumption and additional risk factors associated with microscopic colitis: Case-control study.

BACKGROUND: Microscopic colitis has now emerged as a common cause of chronic diarrhoea, but its aetiology remains unknown. Some studies suggest that commonly prescribed drugs and other additional risk factors may be triggers. AIMS: To evaluate the effects of drug intake and other risk factors on microscopic colitis patients.
METHODS: A prospective, case-control study with all consecutive adult patients referred to the Hospital General de Tomelloso (Ciudad Real, Spain) for chronic watery diarrhoea (from 2008 to 2011) was performed. Microscopic colitis was diagnosed following the commonly accepted histopathological criteria.
RESULTS: 46 consecutive new cases of microscopic colitis and 317 chronic diarrhoea controls were recruited. Five independent risk factors significantly associated with microscopic colitis were identified: Abdominal pain (OR 3.25; 95%CI, 1.49-7.08), weight loss (OR 2.67; 95%CI, 1.16-6.15), celiac disease (OR 15.3; 95%CI, 3.70-63.5), topiramate intake (OR 13.6; 95%CI, 1.84- 100.8), and older age at diagnosis (OR 1 year increase 1.022; 95%CI, 1.002-1.042). Use of non-steroidal anti-inflammatory drugs was associated with microscopic colitis in the subgroup of patients who fulfilled irritable bowel syndrome criteria (38.5% vs. 10.8%; p < 0.017).
CONCLUSIONS: Microscopic colitis is associated with autoimmune disease, an increased age at diagnosis, topiramate intake and only in a sub-group of irritable bowel disease patients with non-steroidal anti-inflammatory drugs.