PURPOSE:This study was designed to determine whether anorectal physiology testing significantly altered patient management in the setting of fecal incontinence.METHODS:Patients referred to the anorectal physiology laboratory for evaluation of fecal incontinence were prospectively interviewed and examined by a colon and rectal surgeon. A decision to treat either medically or surgically was reached. The patients underwent physiologic testing with transanal ultrasound, pudendal nerve terminal motor latency, and anorectal manometry. A panel of board‐certified colon and rectal surgeons then reviewed the history and physical examination, as well as the anorectal physiology tests, of each patient and reached a consensus on management. Management plans before and after physiologic evaluation were compared.RESULTS:Ninety patients (6 males) were entered into the study. The patients were divided in two groups: those with pretest medical management plans (n=45) and those with pretest surgical management plans (n=45). A change in management was noted in nine patients (10 percent). In the medical management group, the management changed from medical to surgical therapy in five patients. Transanal ultrasound detected anal sphincter defects in all patients who changed from medical to surgical management but in only 10 percent of those who remained under medical management (P=0.0001). In the surgical management group, three patients (7 percent) changed from surgical to medical therapy and one patient (2 percent) changed from sphincteroplasty to neosphincter. Transanal ultrasound detected a limited anal sphincter defect in one patient (33 percent) who changed from surgical to medical management and a significant defect in all 41 patients (100 percent) who remained under surgical management (P=0.003).CONCLUSIONS:Anorectal physiology testing is useful in the evaluation of patients with fecal incontinence. Without the information obtained from physiologic testing, 11 percent of patients who may have benefited from surgery would not have been given this option, and 7 percent of patients could have potentially undergone unnecessary surgery. Transanal ultrasound is the study most likely to change a patient's management plan.