Abstract: Aim The effect and adverse events of olsalazine sodium were evaluated and compared with those of sulphasalazine in 149 patients with mild to moderate ulcerative colitis (active). Methods 107 patients with ulcerative colitis were randomized to receive 4 g of sulphasalazine or 2 g of olsalazine daily and were followed up for 8 weeks. Another 42 Patients were given known olsalazine. The enteroscopy were done before and after treat-ment. Results The total effective rate of olsalazine was 84.61%. The complete remission of synptoms, in clinical observation enteroscopy and histological was 75.00%, 34.62% and 55.77%, respectively, and comparable to that in SASP and opened study. The main adverse event was diarrhea. Conclusion Olsalazine sodium is effective in the treatmeat of active ulcerative colitis. The effect is comparable to SASP. The main ad-verse event was diarrhea.

Key words: olsalazine, ulcerative colitis, double-blind