Intestinal polyps are apparent growths of the intestine's mucous membrane, which protrude into its lumen. The mucous membrane is composed of cells of a characteristic appearance, structure and functionality, which line the internal organs. The intestinal mucous membrane of the smaller intestine is very segmented. It protrudes into villi and plicae in order to increase the surface area for the absorption of nutrients. In the larger intestine, this segmentation is very limited, the mucosa is quite smooth. Intestinal polyps can be a risk factor for the appearance of malignant tumors of the larger intestine, which is why they always should be examined.
Development of intestinal polyps
A risk factor for development of intestinal polyps is a congenital predisposition, which can run in the family. This is known as a familial polyposis, which, if untreated, can lead to a carcinoma of the larger intestine even at an early age. Among other risk factors is a diet rich in red meat, animal fats,drinking large quantities of beer and alcohol in general, smoking, obesity and low physical activity. On the other hand, vegetables, chicken meat and fish seem likely to have a positive influence on the intestinal mucosa. The most severe consequence of intestinal polyps is a colorectal carcinoma. This is one of the most common cancers in the world. Unfortunately this disease is still very often only discovered in its late stage and is fatal.
Types of intestinal polyps
Polyps are raised areas in the intestine's mucosa, which do not appear under normal circumstances. The appear particularly in the larger intestine and are a risk factor for the development of malignant cancer. Polyps can be divided into malignant polyps and benign polyps.
Malignant polyps, known as adenomatous polyps or adenomas, are the most common kind of polyps. They develop from glands and are among the benign tumors, there however is a risk of them them turning into a malignant tumor, called adenocarcinoma ( a colorectal carcinoma). The polyp usually grows slowly, through the period of several years, however with its increasing size comes an increased probability of a malignant turn. The severity of the risk of the appearance of a malignant tumor is then decided based on the size of the polyp. It is estimated that up to the size of 1 cm in diameter, the risk is 1%, up to the size of 2 cm the risk is 10% and at the size of over 2 cm in diameter the risk can be up to 40%. The risk of a malignant change is also based on the type of the polyp, divided into tubular, villous and tubovillous adenoma. The highest risk is in villous adenomas. Up to 75% of all adenomas appear in the left half of the larger intestine.
Benign polyps constitute an 11% of all polyps. No tumors develop from these polyps. We recognize:
- Hyperplastic polyp is the most common of the benign polyps, reaching the size of under 1 cm.
- Juvenile polyp appears in children and young persons. If appearing individually, they present no risk for the patient. If multiple polyps appear, the development of malignant tumours cannot be ruled out.
- Inflammatory polyp can accompany inflammatory diseases of the intestine, such as Crohn's disease or ulcerous colitis.
Symptoms of intestinal polyps
Intestinal polyps are usually signified by bleeding into the intestine. However, the bleeding is usually hidden (occult), not visible by naked eye. This can only be discovered using special testing, which is simple, painless and short and should be underwent by every adult over the age of 50 at least once a year. These test are an important step in discovering polyps. Sometimes the intestinal polyp can manifest through visible bleeding, where the blood is bright red, stuck to the surface of the stool. In the case the polyp has a longer stalk, in can prolapse out of the anus. Blood in stool doesn't only imply polyps, so it is necessary to visit a doctor and undergo a thorough examination and treatment. If there is a suspicion of polyps, a colonoscopy is performed, a type of endoscopic examination where the doctor inserts a tubular probe through the anus into the large intestine and should he discover a polyp, removes it whole. This necessary for biopsy. If the biopsy confirms a cancerous polyp, the following treatment will be decided by an oncologist.
Prevention of polyps
Polyps can manifest in anybody. If you suspect you are threatened by this disease or that anyone related is, visit a doctor as soon as possible. If you are over 50 years old, don't forget your regular occult blood stool exams and regular check ups. Healthy lifestyle is also recommended, paying attention especially to having enough fiber in your diet.