Twenty-eight patients who underwent sphincter-saving proctocolectomy and formation of an ileoanal reservoir had clinical evaluation of resting and maximal anal sphincter pressures and perfused catheter manometry. The clinical estimate of resting tone, heretofore believe to be a good predictive parameter of postoperative function, was inaccurate. This suggests the advisability of manometric evaluation. There were significant changes in sphincter pressures postoperatively. Operation did not effect the preoperative electromyographic findings of the puborectalis muscle and external sphincter in our small postoperative population. The mechanism by which operation might influence these parameters has been discussed. Factors such as parity and the descending perineum syndrome may effect continence. Due to the length of time the sphincter is required to function in these patients and the multiplicity of factors involved, we believe that long-term studies are needed.