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Polyps of the Colon and Rectum


Anthony Villano

, MD, Fox Chase Cancer Center

Reviewed/Revised Oct 2023
Topic Resources

A polyp is a growth of tissue that projects from the wall of a hollow space, such as the intestines.

Polyps vary considerably in size, and the bigger the polyp, the greater the risk that it is cancerous or likely to become cancerous (that is, they are precancerous).

Polyps may grow with or without a stalk (a thin piece of tissue that joins the polyp to the intestinal wall, similar to how the neck joins the head to the body).

There are many types of polyps but doctors typically divide them into

  • Adenomatous polyps

  • Nonadenomatous polyps

Adenomatous polyps, which consist primarily of glandular cells that line the inside of the large intestine, are likely precancerous.

Nonadenomatous polyps can develop from many cell types, including the nonglandular cells that line the intestine, fat cells, and muscle cells. Some nonadenomatous polyps are caused by other disorders, for example the inflammatory polyps that develop in people with chronic ulcerative colitis. Nonadenomatous polyps are less likely to be precancerous.

Hereditary conditions that cause intestinal polyps

In Peutz-Jeghers syndrome, people have many small polyps in the stomach, small intestine, and large intestine. They also have numerous bluish black spots on their face, inside their mouth, and on their hands and feet. The spots tend to fade by puberty except for those inside the mouth.

People with Peutz-Jeghers syndrome have an increased risk of developing cancer in many organs, particularly the pancreas Pancreatic Cancer Smoking, chronic pancreatitis, obesity, and exposure to certain chemicals are risk factors for pancreatic cancer. Abdominal pain, weight loss, jaundice, and vomiting are some typical symptoms... read more , stomach Stomach Cancer A Helicobacter pylori infection is a major risk factor for stomach cancer. Vague abdominal discomfort, weight loss, and weakness are some typical symptoms. Diagnosis includes endoscopy... read more Stomach Cancer , small intestine Small-Intestine Cancer Blood in the stool is a common symptom, but sometimes the cancer blocks the intestine, causing crampy abdominal pain and vomiting. The diagnosis is based on various intestinal viewing techniques... read more , colon Colorectal Cancer Family history and some dietary factors (low fiber, high fat) increase a person’s risk of colorectal cancer. Typical symptoms include bleeding during a bowel movement, fatigue, and weakness... read more Colorectal Cancer , breast Breast Cancer Breast cancer occurs when cells in the breast become abnormal and divide into more cells uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes ... read more Breast Cancer , lung Lung Cancer Lung cancer is the leading cause of cancer death in both men and women. About 85% of cases are related to cigarette smoking. One common symptom is a persistent cough or a change in the character... read more Lung Cancer , testes Testicular Cancer Testicular cancer occurs in the testes, the 2 small organs in males that make sperm. Testicular cancer is most common among young men but usually curable. Usually a painless lump is present... read more Testicular Cancer , ovaries Ovarian Cancer, Fallopian Tube Cancer, and Peritoneal Cancer Ovarian cancer is cancer of the ovaries. It is related to fallopian tube cancer, which develops in the tubes that lead from the ovaries to the uterus, and peritoneal cancer, which is cancer... read more , and uterus Cancer of the Uterus The most common type of cancer of the uterus develops in the lining of the uterus (endometrium) and is called endometrial cancer. Endometrial cancer usually affects women after menopause. It... read more Cancer of the Uterus .

Examples of Peutz-Jeghers Syndrome

Symptoms of Colorectal Polyps

Most polyps do not cause symptoms. When they do, the most common symptom is bleeding from the rectum.

A large polyp may cause cramps, abdominal pain, obstruction, or intussusception Intussusception Intussusception is a disorder in which one segment of the intestine slides into another, much like the parts of a telescope. The affected segments block the bowel and block blood flow. The cause... read more (one segment of the intestine slides into another, much like the parts of a telescope). Large polyps with tiny fingerlike projections that can be seen only with a microscope (called villous adenomas) may excrete water and salts, causing excessive watery diarrhea that may result in low levels of potassium in the blood (hypokalemia Hypokalemia (Low Level of Potassium in the Blood) In hypokalemia, the level of potassium in blood is too low. A low potassium level has many causes but usually results from vomiting, diarrhea, adrenal gland disorders, or use of diuretics. A... read more ).

Occasionally, a rectal polyp on a long stalk drops down and dangles through the anus.

Diagnosis of Colorectal Polyps

  • For polyps, colonoscopy

  • For Peutz-Jeghers syndrome, genetic testing

A doctor may be able to feel polyps by inserting a gloved finger into the rectum, but usually polyps are discovered when colonoscopy is done to examine the entire large intestine. This complete and reliable examination is done because more than one polyp is often present and any may be cancerous.

During colonoscopy, any polyps seen are removed and evaluated for possible cancer.

Colonoscopy: Obtaining a Biopsy Sample

Monitoring of Peutz-Jeghers syndrome

People who have bluish black spots on their lips or in their mouth and/or have 2 or more polyps in their digestive tract or a family history of Peutz-Jeghers syndrome should have a blood test to determine whether they have the gene mutations that cause this disorder.

Once people are diagnosed with Peutz-Jeghers syndrome, doctors recommend they have regular tests to detect the various cancers that can develop with this disorder.

Treatment of Colorectal Polyps

  • Removal during colonoscopy or sometimes surgery

Doctors generally recommend removing all polyps from the large intestine and rectum because of their potential to become cancerous. Doctors remove polyps during a colonoscopy procedure using the biopsy forceps or by using an electrified wire loop (snare). If a polyp cannot be removed during colonoscopy, abdominal surgery may be needed.

If a polyp is found to be cancerous, need for additional treatment depends on whether the cancer is likely to have spread. The risk of spread is determined by microscopic examination of the polyp. If the risk is low, no further treatment is necessary. If the risk is high, the affected segment of the large intestine is removed surgically, and the cut ends of the intestine are rejoined (see also treatment of colorectal cancer Treatment Family history and some dietary factors (low fiber, high fat) increase a person’s risk of colorectal cancer. Typical symptoms include bleeding during a bowel movement, fatigue, and weakness... read more Treatment ).

When a person has a polyp removed, doctors do colonoscopy to examine the entire large intestine and rectum. Follow-up colonoscopies are done at different intervals depending on many factors including the number, size, and type of the polyps. If colonoscopy cannot be done, a barium enema x-ray X-Ray Studies of the Digestive Tract X-rays often are used to evaluate digestive problems. Standard x-rays ( plain x-rays) can show some blockages or paralysis of the digestive tract, or abnormal air patterns in the abdominal cavity... read more or computed tomography (CT) colonography may be done to view the large intestine.

Prevention of Colorectal Polyps

To prevent new polyps from forming in people who have polyps or colon cancer, doctors may give aspirin and coxibs (COX-2 inhibitors).

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