Twenty-five patients with ileo-anal "reservoir" have been evaluated by clinical examination, manometry, proctography, endoscopy and biopsy, at least six months from the closure of ileostomy. 80% of them presented with a satisfactory condition, although only one third reached a normal function; 20% suffered for one or more dysfunctions which lead to a variable degree of social handicap. The most frequent dysfunctions were incontinence (13 patients), urgency (10), frequency (9), pouchitis (6), incapacity to evacuate (2). The mean values at manometry showed a halved anal tone, a slightly impaired external sphincter, a halved compliance of the pouch in comparison to normal rectum. Radiology demonstrated that half the patients with dysfunctions had a reduced motility of the pouch and anomalies in sphincter coordination. Endoscopy and biopsies demonstrated inflammation in 12 patients and 6 of them developed an acute pouchitis. From a general point of view, apart from particular conditions, it has been impossible to correlate clinical dysfunctions with a specific abnormality at the instrumental evaluation. Therefore, while good results are assumed to be due to a normally restored anatomical and motility condition, we must recognize that most clinical dysfunctions are not univocally correlated to abnormalities of the pouch or of the sphincteric apparatus.