Long term metabolic consequences of ileal pouch-anal anastomosis for ulcerative colitis

OBJECTIVES: Chronic inflammation in the ileal pouch is the most significant late complication after ileal pouch-anal anastomosis (IPAA). It leads to c hanges in mucosal morphology, with consequent decreased vitamin B-12, bile acid and cholesterol absorption documented. The aims of this study were to evaluate long term metabolic consequences at least 5 yr after IPAA and the influence of pouchitis on pouch histology and on bile acid, lipid, and vita min B-12, A, E, and D metabolism. METHODS: A total of 104 patients with a J-pouch who were operated on betwee n 1985 and 1994, as well as 21 ulcerative colitis patients with a conventio nal ileostomy were enrolled for the study. Routine blood tests, vitamin sta tus, vitamin B-12 levels, and bile acid absorption were determined, as well as endoscopy with biopsies. The pouchitis disease activity index (PDAI) wa s calculated. On the basis of histology, IPAA patients were divided into th ree subgroups: 1) those with no villous atrophy, 2) those with partial vill ous atrophy, and 3) those with subtotal or total villous atrophy. RESULTS: Incidence of pouchitis was 42.3%, and was strongly associated with villous atrophy. In IPAA patients with subtotal or total villous atrophy ( 32.7%), serum levels of albumin, calcium, total cholesterol, triglycerides, and vitamin E were significantly reduced (p < 0.05). The lowest bile acid and vitamin B-12 absorption rates were seen in patients with inflammation i n the proximal limb. Vitamin D deficiency was seen in 10.6%, and vitamin A and B-12 deficiency in approximately 5% of IPAA patients. CONCLUSIONS: Metabolic consequences after IPAA are associated with pouchiti s, grade of villous atrophy, and extent of inflammation in the remaining il eum. Patients with active chronic inflammation need long term follow-up. (C ) 2001 by Am. Coll. of Gastroenterology.