 The aim of the study is to assess the safety and efficacy of an investigational agent, AST-120, in treating patients with active pouchitis. This is an open-label trial which means that all patients will receive AST-120 in 2g sachets packetsthree times a day for 4 weeks. All antibiotics, probiotics and nutritional agents must have been discontinued for at least 2 weeks prior to study entry. An initial group of 10 patients will be enrolled. If there are no serious adverse events associated with the study drug and at least 3 of the 10 patients respond, a second group of 10 patients will be enrolled. In the second group of patients, those patients who are considered responders or who are in remission are eligible to receive open-label AST-120 for as long as response is maintained up to a maximum of 52 weeks. Patients will have clinic visits at the start of the study and at week 4. If continuing on open label AST-120 after week 4, patients will have clinic visits every 12 weeks to assess the continuing safety and efficacy of AST-120. Endoscopies will be performed at the start of the study, week 4, week 28, week 52 or early termination. 