Forty patients with third-degree hemorrhoids were randomized in two groups. Seventeen patients had a Milligan hemorrhoidectomy combined with anal dilatation and 23 had hemorrhoidectomy only. Anal manometry was carried out preoperatively at three, six, and 12 months postoperatively. Maximum resting pressure decreased significantly in both groups after surgery, although a small increase in maximum resting pressure was noticed after six months. A significant decrease in anal pressure was measured in both groups after one year. After one year, three patients in the dilatation group had minor degrees of incontinence compared to none in the nondilated group. In both groups three patients complained of recurrent symptoms of hemorrhoids. It is concluded that the combination of hemorrhoidectomy and anal dilatation does not improve cure rate compared to hemorrhoidectomy alone, but may increase the risk of continence disturbances.