Mild stenosis can be treated with stool softeners or fiber (which come from plant foods) supplements (in pill or powder form). When the narrowing of the anal canal is not too much, an operation called a "sphincterotomy" can be done to correct the problem. This is an operation done on the internal anal sphincter muscle, a round muscle inside the anal canal. In cases where the anal canal becomes very narrow, an operation called an "anoplasty" is done. This is "reconstructive surgery" (also known as "plastic surgery") of the anus.