Hemorrhoids are very common. They result from increased pressure on the anus. This can occur during pregnancy or childbirth, and due to constipation. The pressure causes the normal anal veins and tissue to swell. This tissue can bleed, often during bowel movements.
Hemorrhoids may be caused by:
- Straining during bowel movements
- Constipation
- Sitting for long periods of time, especially on the toilet
- Certain diseases, such as cirrhosis
- Hemorrhoids may be inside or outside the body.
Internal hemorrhoids occur just inside the anus, at the beginning of the rectum. When they are large, they may fall outside (prolapse). The most common problem with internal hemorrhoids is bleeding during bowel movements.
External hemorrhoids occur outside the anus. They can result in difficulty cleaning the area after a bowel movement. If a blood clot forms in an external hemorrhoid, it can be very painful (thrombosed external hemorrhoid).