Table 2. Inclusion criteria.

Male and female patients aged more than 18 years;

Diagnosis of UC established by previous colonoscopy, with consistent histology and clinical course;

UC involving at least the rectosigmoid region; activity confirmed by colonoscopy at the beginning of the study;

Mild-to-moderate relapsing UC, defined as a UCDAI score ranging from three to eight;

Symptoms (relapsing episodes) for less than 4 weeks before study entry;

A minimum endoscopic score of three on the UCDAI at screening (mucosal appearance);

Use of oral 5-ASA at least 4 weeks before study entry at a stable dose (mesalazine at least 1.6 g/day or balsalazide at least 4.5 g/day) and/or use of azathioprine (at least 1.5 mg/kg/day) or 6-mercaptopurine (at least 1 mg/kg/day) at least 3 months before study entry at a stable dose.

ASA, aminosalicylic acid; UC, ulcerative colitis; UCDAI, ulcerative colitis disease activity index.