Olsalazine in the treatment of mild to moderate ulcerative colitis: a randomized, placebo-controlled, double-blind, clinical trial.

Olsalazine, 2 g/day, was compared with placebo in 126 patients with mild or moderate ulcerative colitis. Evaluation after 4 weeks revealed a significant improvement in endoscopic findings in the rectum and sigmoid colon and in the clinical parameters rectal mucus and blood discharge, whereas no significant difference was found between olsalazine and placebo groups in clinical parameters, such as stool frequency and consistency, urge to defecate, abdominal pain and biopsy findings. It is concluded that olsalazine, 2 g/day, is tolerated as well as placebo except that it caused diarrhoea in some patients.