Anal stenosis is a narrowing of the anal canal. Long-term inflammation in the rectum sometimes causes scarring. Repeated ulceration and healing can also result in scar tissue, as can surgical procedures for hemorrhoids, skin tags, anal dilation, and sphincterectomy. Scar tissue is not as flexible as healthy tissue, and the gradual build-up can narrow and constrict the rectal or anal canal, resulting in a rectal or anal narrowing, or stricture (also called stenosis).
Excessive scar tissue can be surgically removed, or they can try balloon dilation. Mine is not bad enough to require that yet.