What is a polyp?
A polyp is a protrusion that grows from the inner lining of the colon. Polyps are usually classified into neoplastic (tumors) or non-neoplastic (not tumors). One type of neoplastic polyp is called an adenoma. This is the type of polyp that has the potential to grow into cancer (though most never do) and one main goal of colonoscopy is to remove these when they are found. Up to 75% of polyps detected by colonoscopy are adenomas.
How common are Adenomatous Polyps?
The prevalence of adenomas is subject to wide geographic variation. The overall prevalence of adenomas in the United States is about 40%. Prevalence increases with age, and the age-adjusted prevalence of polyps is 30% higher in men than in women.
What are the Symptoms of Polyps?
Polyps usually cause no symptoms. Most of the polyps are found during screening colonoscopy. Larger polyps however, may cause rectal bleeding, rectal prolapse, abdominal pain or change of bowel habits.
Do all Polyps look the same?
There are different appearances to polyps. The two most commonly encountered polyps are called pedunculated and sessile. Pedunculated polyps have a head and a stalk (they may look like a mushroom). Sessile polyps are raised above the surface but do not have a stalk. Less common are flat polyps and depressed polyps.
Colonoscopic view of a pedunculated polyp
Colonoscopic view of a sessile polyp
How Polyps are removed?
Polyps are usually removed during colonoscopy. The method used depends on the size of the polyp. Larger polyps are most commonly removed using snare cautery. A snare is an instrument that looks like a lasso and is made of a thin metal wire. Cautery refers to burning of the tissue which is produced when electrical current is passed through the wire. This is done to prevent bleeding. Smaller polyps may be removed using a snipping device called a biopsy forceps. Removing a polyp is a procedure referred to as "polypectomy"
Colonoscopic view of a small sessile polyp
A snare is applied around the polyp
The post-polypectomy appearance of the mucosa
What are the risks associated with polypectomy?
Polypectomy is a very safe procedure. Polyp removal has been shown to effectively decrease the risk of developing colon cancer. There is a very small risk of bleeding or perforation (poking a hole in the colon).
1. Bleeding may occur immediately after removing a polyp and this may be stopped by injecting epinephrine at the site of the polypectomy. Bleeding however may occur up to 29 days following a polypectomy; this is referred to as delayed hemorrhage. If you experience rectal bleeding a few days after having a polypectomy, call your doctor immediately or report to the nearest emergency room. In most cases, bleeding stops spontaneously. In some cases a repeat colonoscopy may be indicated to stop the bleeding.
2. Perforation means rupture of the part of the colon from which a polyp was removed. This may happen after removing a rather large polyp using a cautery. Symptoms typically include abdominal pain and fever. You should call your doctor immediately or report to the nearest emergency room if you experience such symptoms.
