Gracilis muscle transposition for faecal incontinence. Transposition of the gracilis muscle for faecal incontinence was performed in 13 patients. Six gained satisfactory continence, four were improved, two did not benefit from the operation and one patient died from intercurrent disease before closure of a pre-existing colostomy. Anal manometry compared with a control group showed no alteration in resting and pressure at a median of 35 mmHg (range 5-63 mmHg), whereas maximum squeeze pressure increased from a median of 38 mmHg (range 5-79 mmHg) to 59 mmHg (range 10-143 mmHg) (P = 0.041) which was, however, significantly lower than 130 mmHg (range 81-236 mmHg) in the control group. All patients who benefited from the operation had an increase in maximum squeeze pressure. The ability to retain a viscous fluid in the rectum was measured in seven patients, four of whom had gained satisfactory continence and three of whom had improved continence. They were able to retain a median volume of 200 ml (range 50-225 ml) without leakage compared with 325 ml (range 250-400 ml) in the control group. These patients could retain the maximum amount of viscous fluid for 5-8 min, whereas all control subjects could do so for more than 15 min. It is concluded that, although gracilis transposition never results in normal continence, acceptable continence may be achieved in selected patients provided careful attention is paid to the technical details of the procedure and provided that systematic postoperative exercises are performed. 