Colorectal polyp removal

Anatomy or system affected: Abdomen, anus, gastrointestinal system, intestines

Definition: The surgical removal of overgrowths of the tissue lining the rectum and colon

Indications and Procedures

Rectal and colon polyps are growths of tissue that occur in the mucous membranes lining the colon and rectum. They are usually not malignant. Common types of colorectal polyps are juvenile polyps, Peutz-Jeghers polyps (hamartomas), hyperplasias, adenomas, and mixed hyperplastic-adenomatous polyps. Adenomas are both the most dangerous and the most common type of colon polyp.

Rectal or colon polyps are removed when they are found, even if they cause no symptoms, because identifying the kind of polyp helps doctors determine whether cancer is likely to develop. The type of polyp is determined in the laboratory after surgical removal, using microscopic techniques.

The presence of polyps does not mean that a patient has cancer, although larger polyps (greater than one centimeter) indicate a higher risk for cancer than do smaller ones. Certain types of polyps also are more likely than others to develop into cancer. Hyperplasias are polyps with no potential to develop into cancer. Juvenile polyps and Peutz-Jeghers polyps are associated with inherited disorders that indicate an increased risk for colon cancer, but they do not always develop into malignant tumors. Colorectal adenomas are particularly dangerous when they occur in conjunction with a genetic condition known as familial adenomatous polyposis (FAP). In patients with FAP, untreated colorectal adenomas develop into colon cancer virtually 100 percent of the time. Mixed hyperplastic-adenomatous polyps, although not as risky as pure adenomas, can develop into colon cancer, and patients with a diagnosis of this type of polyp should be closely monitored.

Colon polyps often cause no symptoms. They are usually detected by routine screening for colorectal cancers. The most common symptoms, when they occur, are bleeding from the anus (visible on underwear or toilet paper), constipation or diarrhea lasting more than a week, and blood in the stool, which can appear as red streaks or an overall darkening of fecal matter. The fecal occult blood test will detect blood that is not visible.

When polyps are suspected, the physician will perform a rectal examination or special tests such as barium enema X-rays, flexible sigmoidoscopy, or colonoscopy. In a rectal examination, the doctor feels the rectal tissue with his or her fingers, looking for abnormalities. Barium makes healthy intestinal tissue look white on an X-ray, and polyps appear dark against the white background. The sigmoidoscope is a flexible fiber-optic tube that can be inserted through the anus. The tube has a small video camera and a light so that the doctor can visualize the lower third of the large intestine. Colonoscopy is similar to sigmoidoscopy, but the colonoscope allows the physician to visualize the entire intestine.

Removal is most commonly accomplished using colonoscopy to visualize the polyps and specialized forceps to detach and remove the growths. Snare forceps can be used to surround a polyp and cut it from the lining of the colon or rectum. Other methods of removal include a laser beam, burning, or ultrasound, depending on the size of the polyp. Bleeding during the procedure can be controlled with electrocautery forceps, which use heat to sever the polyp from the surrounding healthy tissue and seal off blood vessels, or by pressing epinephrine-soaked gauze against the removal site.

Special precautions must be taken during surgery to remove gas from the colon so that the combustion of hydrogen or methane gas does not occur. These gases are normally produced by bacteria that inhabit the colon.

A polyp in the lower portion of the colon may be removed using similar procedures during the sigmoidoscopy. In some cases, the patient may undergo surgery to remove the polyp through the abdomen.

Uses and Complications

Since colonoscopy is somewhat uncomfortable for the patient, sedatives are usually given, but general anesthesia is usually not necessary. Rectal and colon polyp removal is typically done as an outpatient procedure.

Because of the gas that enters the intestine during the procedure, patients may experience bloating, pressure, and intestinal cramps in the twenty-four hours following removal. This discomfort subsides as the gas passes out of the intestine.

Repeat colonoscopy should be performed so that recurrent polyps can be removed and examined for malignancy. Colorectal cancer is the second leading cause of cancer deaths in the United States, and the majority of these cancers arise from colorectal polyps.

Bibliography

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Longo, Walter E., and John M. A. Northover, eds. Reoperative Colon and Rectal Surgery. Martin Dunitz, 2003.

Longstreth, George F. "Colorectal Polyps." MedlinePlus, medlineplus.gov/ency/article/000266.htm. Accessed 20 July 2023.

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