In most cases, the colon polyps do not cause any symptoms. If the polyps are very large, they can also prevent the passage of the intestinal contents, causing constipation and pain. This can lead to blood in the stool or in rare cases to colic.
Most often, colon polyps are found in the last section of the intestine, the rectum. Colon polyps can occur at a single location, occasionally at a few locations in the colon, or they can accumulate as a so-called polyposis syndrome in the entire colon (>100 polyps in the entire colon). These syndromes are hereditary, so a large number of polyps can occur in the intestine even in young patients.
The following polyposis syndromes are known:
- Familial juvenile polyposis
- Peutz-Jeghers Syndrome
- Cowden Syndrome
- Familial adenomatous polyposis = FAP
Removed polyps are always evaluated histologically (under the microscope), as this allows to determine how dangerous the polyp was or what risk still exists. There are different histological types of colon polyps, which have a different risk of degeneration: Inflammatory and hyperplastic polyps have no increased risk of cancer. Hamartomas have a slightly increased risk of cancer.
Adenomas have an increased cancer risk of up to 40% depending on the subtype. This form of cancer development is also called adenoma carcinoma sequence. This means that over time an existing adenoma can develop into a carcinoma – i.e. intestinal cancer.
In familial adenomatous polyposis there is a cancer risk of over 90%, therefore the colon must be removed (colectomy) and a check-up every 6 months. Regular colonoscopy is also useful for control in the case of intestinal polyps without cancer risk. The aim is to determine whether the site where the colon polyp was removed still looks unremarkable and whether new polyps have grown in other areas.
