O2-17. Determinants of optimal bowel function in restorative proctocolectomy – physiological differences contributing to pouch function
Marie Louise Sunde [1,2], Petr Ricanek , Tom Øresland [1,2], Jørgen Johansen [1,2], Nazir Naimy , Arne Færden 
Affiliates:  Akershus University Hospital,  University of Oslo.
Restorative proctocolectomy is the treatment of choice in patients with ulcerative colitis. Variability in functional outcome is to a large extent unexplained. The aim of this study was to perform physiological tests and endoscopic examination in well and poorly functioning pouches to determine factors contributing to functional outcome.
All patients undergoing restorative proctocolectomy between 2000 and 2013 were interviewed using a pouch functioning score. The best and worst functioning patients were invited to join the study, and examined with a barostat simultaneously measuring pouch pressure and volume, and with a pouch endoscopy.
47 of 60 eligible patients agreed to participate. The most significant physiological parameter that differed between the groups was pouch volume at first sensation, urge and discomfort (p value <0.001). Urge volumes were 213 (CI 175-252) ml for poorly and 352 (CI 305-401) ml for well functioning pouches. Histological occurrence of pouchitis and type of anastomosis also differed between the groups. The remaining rectal cuff was longer in the poorly functioning group, however non significant.
Pouch volume, histological findings of pouchitis and type of anastomosis were significantly different between well and poorly functioning pouches, with volume being the most dominant predictor.