Duration of remission and long-term prognosis according to the extent of disease in patients with ulcerative colitis on continuous mesalamine treatment.

Aims  To describe the long-term prognosis of ulcerative colitis (UC) and to establish whether a correlation exists between the different anatomic locations of the disease and the risk of relapse in a homogeneous cohort of patients with UC in clinical remission, all treated with fixed doses of oral mesalamine from the date of enrolment to the appearance of the first relapse. Method  We distinguished the patients with pancolitis and left-sided colitis from those with distal colitis. The follow-up lasted up to 5 and 6 years for the patients with pancolitis and left-sided colitis, respectively, and up to 9 years for the patients with distal colitis. Results  One hundred and fifty patients satisfied the enrolment criteria. We registered 19 drop-outs. All the patients had relapsed within 9 years. In most cases relapses arose within 2–3 years. The patients with pancolitis had a shorter time to relapse (100% relapsed after 5 years) than the patients with left-sided colitis (100% after 6 years) or distal colitis (100% after 9 years). None of the enrolled patients developed a cancer. Extraintestinal complications were observed in 9% of cases and surgery was needed in five patients only. Conclusion  The first 2–3 years after the enrolment of patients with UC in remission was the period at higher risk of relapse. No relationship was found between the different anatomic locations of the disease and the risk of relapse, even if distal colitis showed a slightly better course.