The results of total abdominal colectomy (TAC) with ileorectal anastomosis as a treatment for colonic inertia (CI) were prospectively assessed. One hundred sixty-three patients were evaluated for chronic constipation between July 1988 and November 1990. Patients underwent pancolonic transit times, anorectal manometry, cinedefecography (CD), and electromyography (EMG). CI was defined as diffuse marker delay on transit study without evidence of puborectalis contraction on CD or EMG. Sixteen patients (10 percent; 15 females and 1 male) with a mean age of 45 years (range, 24-75 years) with CI underwent TAC. Preoperative bowel frequency ranged from three per week to one per month; all 16 patients evacuated only with high doses of laxatives, enemas, or both. TAC was performed with no postoperative mortality or major morbidity; three patients were readmitted four times for successful conservative treatment of partial small bowel obstruction. At a mean follow-up of 15 months (range, 2-35 months), these 16 patients reported a mean frequency of spontaneous bowel evacuations of 3.5 per day (range, one to six per day). Patient satisfaction with the operation was "excellent" or "good" in 15 cases (94 percent). Thorough preoperative physiologic evaluation permits the selection of a small group of patients with CI who may benefit tremendously from TAC.