Physiological parameters influencing function in restorative proctocolectomy and ileo-pouch-anal anastomosis

Ileo-pouch-anal function has been assessed in 30 patients after restorative proctocolectomy and compared with age- and sex-matched controls. Median resting anal canal pressure was only 42 cmH2O (7-113 cmH2O) compared with 100 cmH2O (46-114 cmH2O) in controls (P less than 0.005). Maximum squeeze anal pressures were also significantly lower in pouch patients: 87 cmH2O (25-180 cmH2O) than controls: 143 cmH2O (114-171 cmH2O) (P less than 0.01). The recto-anal inhibitory reflex was absent in all pouch patients but was present in all controls. Maximum pouch or ileal pressures exceeded resting anal canal pressures in three patients. Median volume at first leak during saline infusion was 320 ml (60 ml-no leak) in pouch patients whereas the majority of controls had no leakage (median, none; 450 ml-no leak; P less than 0.05). Threshold pouch sensation (median, 50 ml (0-250 ml] did not differ from rectal sensation in controls (50 ml (0-180 ml] but pouches were less compliant than a normal rectum, median 6.8 ml/cmH2O (2.1-17 ml/cmH2O) and 11.6 ml/cmH2O (4.7-16.2 ml/cmH2O) respectively (P less than 0.05). In patients who had an episode of pelvic sepsis (n = 8) the average number of abnormal physiological indices per patient was 3.8, compared with 1.3 in those with no sepsis (P less than 0.05). There was no difference in the number of abnormalities per patient with a J pouch (2.0; n = 19) or a W pouch (1.9; n = 11).