Five patients went on to have drainage of the pelvic sepsis, with resolution of symptoms in only one. Therefore, based on this series, the significance of a pre-sacral collection on MRI in the context of pouchitis is unknown. Beyond this, it is not known how often this finding may be present as a 'normal variant' in patients with normal functioning pouches. The proposed trial would help to guide clinical management of patients with pouchitis and pre-sacral collections.