Why does my anus hurt when I defecate?

Pain in the anus may be caused by anal fissure. The occurrence of anal fissure will cause anal pain during defecation. Diseases such as hemorrhoids and some rectal cancers may also cause these painful symptoms.

1. Anal pain is a subjective feeling of the patient and there is no objective measurement indicator. Depending on the nature and degree of pain, it can be divided into severe pain, heavy pain, and dull pain. Anal pain is mainly caused by diseases of the anal canal itself, such as anal fissure, which manifests as local pain in the anus; it is caused by diseases around the anorectal canal, such as anorectal abscess, which manifests as pain slightly away from the anus.

2. External hemorrhoids cause anal pain during defecation: mainly characterized by heaviness and burning pain, manifested as a localized lump at the edge of the anus, which is hard, smooth, shiny and obviously tender. It is mostly caused by fatigue, straining during defecation, or surgical stimulation.

3. Anal pain caused by incarcerated internal hemorrhoids: mainly characterized by distension and burning pain. It is mostly due to varicose veins, damaged blood vessels, and thrombosis, which result in restricted tissue circulation and prolapse outside the anus and cannot be retracted. It is common in stage II and III internal hemorrhoids.

4. Anal fissures cause anal pain during defecation: When constipated, the dry and hard feces will be expelled from the body by the patient with force, which will scratch or burst the anal tissue, causing severe pain. Long-term anal fissures may cause continuous spasm of the internal sphincter due to the stimulation of defecation, causing severe and persistent pain in the ulcer fissure; it can often last for several hours, and the patient will be restless and in great pain.

5. Rectal cancer causes anal pain: There is no pain in the early stage. Later, as the tumor grows and ruptures, the anus may feel heavy and painful. Common symptoms include changes in bowel habits, bloody stools, abdominal distension, abdominal pain, and weight loss. If the patient has the above symptoms, he should seek diagnosis and treatment from a specialist in time.