Does colitis associated with primary sclerosing cholangitis represent an actual subset of ulcerative colitis?

The clinical course and endoscopic features of colitis associated with primary sclerosing cholangitis have not been well documented.Since 1980, a total of 485 patients with ulcerative colitis have been seen in our departments. During this period, we experienced 6 patients with primary sclerosing cholangitis, 4 of whom had ulcerative colitis concomitantly.Colitis preceded primary sclerosing cholangitis in 3 of the 4 patients. There were 2 males and 2 females. One patient had left-sided colitis while 3 had total colitis, 1 with a first attack and 3 with relapsing-remitting type. Two of the 4 patients had colonoscopically dominant inflammation in the proximal colon with continuous histological inflammation from the rectum to the proximal colon. Three colitic patients have been well controlled with oral sulfasalzine or mesalazine administration. Only 1 female patient had been hospitalized twice for moderately severe attacks of ulcerative colitis that required systemic prednisolone administration, however, this patient quickly responded to this treatment for each admission.Colitis associated with primary sclerosing cholangitis exhibited atypical colonoscopic findings and exhibited milder disease activity than ulcerative colitis without primary sclerosing cholangitis.