Despite its intermittent course of activity and remission, the good response to salazopyridine and
steroids makes the long-term prognosis of
ulcerative colitis favorable. The number of non-active type
ulcerative colitis is increasing and consequently, the rate of active disease and relapse is decreasing every year. More than 90% of the patients even with disease of 10 or more years are able to work almost with no limits for the daily living. The
colectomy rate in Japan is 4.1% after one year of the onset of the disease and 6.8% after 2 years. Thereafter approximately 1% of the patients undergo surgery yearly. The most common reasons of surgery are complications such as massive
bleeding, perforation or
toxic megacolon. Other indications are chronic continuous disease and cases with frequent relapses. Considering the extension of the disease, about one-third of the total
colitis type and 10% of the left-sided type undergo surgery. The risk of
colonic cancer is higher in patients with total
colitis type and when has had the disease for more than 10 years. Most of the them are flat type poor-differentiated
adenocarcinomas. Therefore patients with total
colitis type for more than 10 years should undergo colonoscopic surveillance.