A colonoscopy done for diagnostic purposes may have several results, ranging from normal results to colon cancer. A normal/negative result means that everything is okay. The following information will help explain the terminology and results related to having a colonoscopy.

Colon Polyps

Polyps are non-cancerous growths which grow in the lining of the intestine. They can occur in numerous body organs but are common in the color. They vary in size from less than a quarter inch to plum size. Some polyps are flat (sessile) and others grow on a stalk (pedunculated.) Polyps are common and occur in 30-50% of adults. The significance of polyps is that some can turn into cancer but are easily removed during a colonoscopy. Most polyps are non-cancerous.

What causes polyps?

The biggest factor in developing colon polyps is being over the age of 50. A family history of colon polyps or colon cancer increases the risk of colon polyps. Other increased risk factors which are not totally understood include a high fat diet, low fiber diet, cigarette smoking, obesity and environmental factors. Uncommon genetic disease may cause high rates of colon cancers in early adulthood (your healthcare provider can determine your risk for this based on your health history and colonoscopy results.

What are the different kinds of polyps?

The two most common types of polyps found during a colonoscopy are hyperplastic and adenomatous. Other types of polyps may also be found in the colon but are less common.

  • Hyperplastic Polyps. Hyperplastic polyps are usually small and located in the end portion of the colon (rectum and sigmoid colon.) They do not develop into malignant tumors (cancer tumors) so are not significant. However, it is sometimes difficult to distinguish their appearance from other types of polyps so they are often removed and analyzed.
  • Adenomatous Polyps About 2/3 of colon polyps are adenoma (adenomatous.) These are the type of polyps that have the potential to become malignant. Adenomas are classified by their size, general appearance and specific features seen on analysis. As a general rule, the larger the adenoma, the more likely it is to become malignant. Some large adenomas may already have some cancer contained within them. It is impossible to tell which adenomas may become malignant so it is best to remove them.
  • Inflammatory Polyps. Inflammatory polyps form in response to an inflammatory process such as colitis. These polyps may also be associated with some parasites, tuberculosis, and diverticular disease. These polyps may become large and pedunculated (a slender stalk) with bleeding or obstruction. Cancer risk with these polyps is extremely rare.
  • Juvenile Polyps. Most commonly occur in children, but occasionally they are found in adults. In adults these are usually benign; however, they may cause bleeding.