Rectopexy is advocated as treatment for solitary rectal ulcer syndrome despite variable outcome. Sixteen patients with this condition, who remained symptomatic after surgery, were examined before and after operation by evacuation proctography and compared with a matched group of seven patients whose symptoms had been relieved, to investigate the effect of rectopexy on rectal configuration or emptying, or both, and to identify any preoperative factor associated with a good outcome. Rectal prolapse, demonstrated in 19 of 23 patients before operation (internal in 12, external in seven), was seen in only one patient after surgery. The rectal axis became more vertical at rest (median 44 degrees before operation versus 35 degrees after surgery, P = 0.006) and on evacuation (median 38 degrees versus 31 degrees, P = 0.023). Preoperative evacuation time was increased in patients with poor outcome (median (range) 22 (8-60)s versus 10 (5-15)s, P = 0.008). Rectopexy successfully treats rectal prolapse in patients with solitary rectal ulcer syndrome and alters rectal configuration. These features, however, are unrelated to outcome. Prolonged preoperative evacuation time, suggesting a defaecatory disorder, may predict poor symptomatic outcome.