Histochemical and metabolic changes in functioning ileal pouches after proctocolectomy for familial adenomatous polyposis and ulcerative colitis.

: Ulcerative colitis and familial adenomatous polyposis may be treated by proctocolectomy with ileal pouch reconstruction, anastomosing the pouch to the anus. We studied 24 patients who underwent this procedure, of whom 12 had ulcerative colitis and 12 had familial adenomatous polyposis. Ileal absorption was investigated and pouch histology assessed more than one year after closure of the protective defunctioning loop ileostomy. The results showed a reduction in bile acid reabsorption and vitamin B12 absorption. These observations were associated with a morphologic transformation in the small bowel mucosa to large bowel mucosa. In 10 of the 12 colitis patients one or more of the histological features of the original disease (such as active inflammation, increased regeneration, atypia) were evident. Histological examination of the biopsies taken from the polyposis patients showed areas with an excess of sialomucins.