Pouchitis: pathophysiology and treatment.

Pouchitis is a potential complication after proctocolectomy and restorative ileoanal anastomosis. It is more frequent in UC than in familial polyposis. Little is known about the etiopathology of pouchitis. Risk factors include the presence of extraintestinal manifestations, primary sclerosing cholangitis, cessation of smoking, and previous course of disease. A host of pathophysiological pathways have been identified as potential mechanisms of pouchitis, which include inflammatory mediators, adhesion molecules, oxygen radical species, p-ANCA, and short-chain fatty acids. The microflora in the pouch may also be an important factor in causing inflammation. The risk of developing cancer in cases of pouchitis has not been established as clearly as in those of UC. Particular attention should be paid to patients who have remaining anorectal mucosa after pouch construction. Experience in the treatment of chronic relapsing and chronic refractory pouchitis is limited. The continuation of conventional anti-inflammatory treatment is successful only in a small percentage of patients. New biological response-modifying therapies which target novel immunoregulatory molecules in IBD will also have impact on the systemic and topical treatment of pouchitis.