This occurs due to an abnormal tear in the skin and lining tissue surrounding the anus. It is caused by over-stretching of the anus due to constipation. It causes a sharp, stabbing pain and bleeding on passing stool with the pain possibly persisting for some time and then subsiding.

The varicose and inflamed veins around the lower end of the bowel, situated in the wall of the anus, are called haemorrhoids or piles. Piles are commonly caused by constipation and straining when passing stools, especially in middle-aged and elderly persons. It is common in pregnancy. It can occur in persons with liver disease and heart disorders. Symptoms include bleeding, pain, itching, and the distended vein may be felt as a lump.