Colon Polyps

What Is It?

Colon polyps are growths of tissue inside the large intestine, also called the colon. Some polyps are mushroom-shaped protrusions on the end of a stalk. Others appear as bumps that lie flat against the intestinal wall.

There are several types of polyps. Most are noncancerous (benign), but one type, the adenomatous polyp, is associated with changes (called mutations) in the DNA of the lining of the colon. These mutations can progress into colon cancer. The larger the polyp, the greater the chance that it contains cancerous cells. For a polyp larger than 1 inch in diameter, there is a 10% chance it is cancerous.

Some people are born with a genetic tendency to develop multiple polyps. Inherited conditions such as familial adenomatous polyposis and Gardner's syndrome can cause hundreds of polyps to grow in the colon and rectum. Without surgery to remove the affected section of the intestine, it is almost certain that at least one of these polyps will turn into cancer by middle age. These two conditions are rare.

Symptoms

Many times, people are not aware they have colon polyps because there are no symptoms. Larger growths can bleed, causing blood in the stool. Sometimes bleeding polyps can cause fatigue and other symptoms of anemia (low levels of red blood cells). On rare occasions, a large polyp can cause diarrhea or secretion of large amounts of potassium. This can cause marked fatigue and muscle weakness.