Polyps of the Colon and Rectum

Polyps are abnormal growths of tissue that arise from the inner or mucosal layer of the large intestine (colon) and protrude into the intestinal canal. Some polyps are flat, while others have a stem. 

Polyps are one of the most common problems affecting the colon and rectum, and they occur in 15 to 20% of the adult population. Although most polyps are benign, the relationship of certain polyps to cancer has been established. 

What are the symptoms of polyps?

Most polyps have no symptoms and are often found incidentally during an endoscopy or x-ray of the bowel. Others, however, can cause bleeding, mucus secretion, impaired bowl function, or, in rare cases, abdominal pain. 

How are polyps diagnosed?

Polyps are diagnosed by direct observation of the inner lining of the colon. There are three types of colorectal endoscopy: rigid sigmoidoscopy, flexible sigmoidoscopy, and colonoscopy. Rigid sigmoidoscopy allows examination of the lower six to eight inches of the large intestine. In flexible sigmoidoscopy, the fourth to third lower part of the colon is examined. Neither rigid nor flexible sigmoidoscopy requires medications and can be performed in the doctor’s office. 

Colonoscopy uses a long, flexible instrument and usually allows inspection of the entire colon. Bowel preparation is necessary, and sedation is often used. 

The colon can also be examined indirectly using the radiography technique with barium enema. This test uses a barium solution to cover the lining of the colon. X-rays are taken, and suspected polyps are often found. 

Although the examination of feces to detect microscopic remains of blood is an important test for disorders of the colon and rectum, a negative result of the test does not rule out the presence of polyps. If a polyp is discovered, a complete colon inspection is necessary since at least 30% of these patients will discover more polyps. 

Is it necessary to treat the polyps?

Because there is no foolproof way to predict whether a polyp will become malignant or not, it is advisable to remove them in their entirety. The vast majority of polyps can be removed by cutting it with an electrometallic wire loop that passes through the instrument. Small polyps can be destroyed simply by touching them with an electric current that coagulates them. 

Most colonic exams that use the flexible colonoscope, including removal of polyps, can be done on an outpatient basis with minimal discomfort. Large polyps may require more than one treatment for a total extraction. Some polyps can not be removed with instruments because of their size and location; in those cases surgery is required. 

Can polyps reappear?

Once a polyp is completely removed, it is very unlikely to reappear; although the factors that caused it do not disappear. At least 30% of people who have had polyps have them again. A physician experienced in the treatment of diseases of the colon and rectum should perform periodic examinations of these patients.