Haemorrhoids are swollen blood vessels in the bottom or rectum. If these veins swell it can cause the vein walls to become stretched and thin. This section of the wall can then get irritated when you have a bowel movement.

Internal haemorrhoids are up inside the rectum and you can’t see or feel them. Because there are not many pain sensors in the rectum they don’t usually hurt. The only sign that they are there may be bleeding.

Occasionally an internal haemorrhoid may “prolapse,” or protrude outside the anus