The role of sphincteroplasty for fecal incontinence reevaluated: a prospective physiologic and functional review. Sixteen female patients (mean age 54.1 years; range 34-74 years) with a 9.8-year (range 1-25 years) history of incontinence to solid stool underwent overlapping sphincteroplasty with internal sphincter imbrication without fecal diversion. All patients were prospectively evaluated with preoperative anorectal manometry, electromyography, and pudendal nerve motor latency assessment, postoperative anorectal manometry, and preoperative and postoperative functional evaluation. Mean and maximal resting pressures increased from 30 mm Hg and 49 mm Hg preoperatively to 40 mm Hg and 57 mm Hg, respectively, postoperatively. Likewise, mean and maximal squeeze pressures increased from 27 mm Hg and 48 mm Hg preoperatively to 39 mm Hg and 73 mm Hg, respectively, postoperatively (P less than 0.01). Furthermore, anal canal high pressure zone length was increased by sphincteroplasty from a mean of 0.9 cm (range 0-3 cm) to a mean of 2.1 cm (range 1-4 cm). These objective physiologic improvements correlated well with subjective functional improvement. Subjectively, functional outcome was rated by patients as excellent in 38 percent, good in 38 percent, fair in 19 percent, and poor in only 5 percent of cases. Overlapping sphincteroplasty with internal sphincter imbrication improves both the anal sphincter physiologic profile and fecal continence. 