Prospective evaluation of ileoanal pouch characteristics measured by barostat

The aim of this study was to evaluate pouch sensory and motor characteristics prospectively during the first postoperative year and to compare those with rectal characteristics.

Twelve patients with an ileoanal J-pouch were studied at 3 and 12 months postoperatively. The results were compared with those obtained in 12 healthy controls. Visceral compliance was assessed using an electronic barostat by a pressure distention procedure, during which sensitivity was also scored by visual analog scales. The response to a meal was assessed during set pressure.

During the first postoperative year, pouch compliance increased significantly from 7.2 +/- 0.6 to 10.7 +/- 0.9 ml/mmHg (rectal compliance 10.6 +/- 1.1 ml/mmHg). The increase in pouch compliance significantly influences the 24-hour stool frequency (P = 0.42). Visceroperception scores remained unchanged. Postprandial decrease in intrabag volume was more pronounced in patients (45 +/- 13 percent at 3 months, 32 +/- 15 percent at 12 months) than in controls (9 +/- 6 percent, < 0.05), and residual postprandial bag volumes were significantly lower in patients at 3 months compared with patients at 12 months.

Ileoanal pouch compliance increases significantly during the first postoperative year to values in the range of rectal compliance. The increase in pouch compliance is related to a decrease in 24-hour stool frequency. Postprandial bag volumes increase during the first postoperative year but remain significantly smaller than in the rectum. Pouch sensitivity does not change.