A polyp is an extra piece of tissue that grows inside your body. Colonic polyps grow in the large intestine, or colon. Most polyps are not dangerous. However, some polyps may turn into cancer or already be cancer. To be safe, doctors remove polyps and test them.

Anyone can get polyps, but certain people are more likely than others. You may have a greater chance of getting polyps if you:

are over age 50
have had polyps before
have a family member with polyps
have a family history of colon cancer

Most colon polyps do not cause symptoms. If you have symptoms, they may include blood on your underwear or on toilet paper after a bowel movement, blood in your stool, or constipation or diarrhea lasting more than a week.

Colon polyps are abnormal outgrowths in the lining of your colon. The causes of colon polyp formation are unknown although it has been associated with a variety of risk factors, including diet and age. Colon polyps may be benign or cancerous, which is why detection of polyps is often always followed by a removal of tissue samples for a quick diagnosis.

Risks

People who are 50 years old or older have been showed to have an increased risk for colon polyp formation. Other risks factors include:

A familial history of polyp formation
An inherited condition which predisposes the person to polyp formation
Ulcerative colitis or Crohn's disease
Previous radiation treatments in the abdomen
Diet high in processed fats, oils and sugars, as well as processed meats
Sedentary lifestyle
Smoking and alcohol consumption
Obesity
Sex

Symptoms

Very small polyps often do not present with any symptoms. When the polyps enlarge, however, painless bleeding, blood in the stool, anemia, and painful abdominal spasms called tenesmus are often experienced. Very large polyps can block the intestines and cause abdominal cramping and pain.
Diagnosis

The five most common diagnostic procedures for colon polyps are:

colonoscopy - in this procedure a thin, fiber optic scope is inserted into the colon through the rectum and the entire colon is viewed through a video monitor. Tissue samples of polyps and lesions may be taken during this procedure for a microscopic examination.
flexible sigmoidoscopy - this allows the visualization of the lower part of the colon
barium enema - in this procedure, a contrast medium (barium) is injected into the colon through the rectum. An X-ray is taken to clearly show the structure of the colon and possible outgrowths like polyps.
fecal occult blood test - this is often used to determine the presence of microscopic amounts of blood in stool, a warning sign for rectal cancer
digital rectal exam - this is useful in determining the presence of polyps in the rectum.

Prevention

Because colon polyps can turn out to be malignant, it is important to regular check your colon for any abnormal growths. Other measures that can lower your risks for colon polyp formation include:

Consumption of a low-fat, high-fiber diet
Maintenance of a healthy body weight
Reduction in weight if obese
Regular exercise
Avoidance of smoking
Moderate alcohol intake
Regular colon screenings, especially if 50 years old and above

Understanding Colon Polyps Recommended Resources:

UT Southwestern Medical Center

Penn State Milton S. Hershey Medical Center