Haemorrhoids. Illustration of a section through a human anus with internal and external haemorrhoids (lower centre, blue). At top is the cavity of the rectum. Haemorrhoids are swollen veins around the lining of the anus. They can occur on the anus (external haemorrhoids), inside the anal canal (internal), or hanging out like a bunch of grapes (protruding). Haemorrhoids are common in pregnancy due to the pressure of the foetus on the rectum. They can also develop as a result of excessive straining to pass hard faeces. Symptoms include pain and bleeding during defecation. Treatment involves eating a high fibre diet and, in severe cases, surgical removal.