Sphincteroplasty: the surgical reconstruction of a sphincter muscle. This usually refers to the procedure that can be done on the muscles of the anal sphincter that control bowel movements. With obstetric trauma during vaginal delivery of a baby, this sphincter can become damaged and result in incontinence of stool. Other conditions can also damage the sphincter and require corrective surgery. With rectal or anal sphincter repair, the ends of the two circular anal muscles that control bowel movements are cut and overlapped onto one another and then sewn into place, creating a complete circle of muscle.
Laura H. Goetz, et al. Overlapping Sphincteroplasty: Is It the Standard of Care? Clin Colon Rectal Surg. 2005 February; 18(1): 22–31.