Familial adenomatous polyposis

By Medically reviewed by hellodoktor


What is familial adenomatous polyposis?

Familial adenomatous polyposis (FAP) is a rare, inherited condition that causes extra tissue (polyps) to form in your large intestine (colon) and rectum. Polyps can also occur in the upper gastrointestinal tract, especially the upper part of your small intestine (duodenum). If untreated, the polyps in the colon and rectum are likely to become cancerous in your 40s.

Most people with familial adenomatous polyposis eventually need surgery to remove the large intestine to prevent cancer. The polyps in the duodenum also can develop cancer, but they can usually be managed by careful monitoring and removing polyps regularly.

How common is familial adenomatous polyposis?

Familial adenomatous polyposis can affect patients at any age. It can be managed by reducing your risk factors. Please discuss with your doctor for further information.


What are the symptoms of familial adenomatous polyposis?

Because 30 percent of people with FAP have a new (spontaneous) mutation and no family history of polyposis, they may not know they have FAP until symptoms of polyps or cancer develop. Symptoms may include bleeding from the rectum, change in bowel habits, abdominal pain, low blood counts or unexplained weight loss. An examination of the colon to determine the cause of symptoms may reveal polyposis.


There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.

When should I see my doctor?

If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.


What causes familial adenomatous polyposis?

FAP is passed from generation to generation in a family. The APC gene is linked to FAP; APC stands for adenomatous polyposis coli. A mutation (alteration) in the APC gene gives a person an increased lifetime risk of developing colorectal cancer or other cancers of the digestive tract.

Risk factors

What increases my risk for familial adenomatous polyposis?

Because familial adenomatous polyposis (FAP) is inherited, a family history of the disease is the main risk factor.

Diagnosis & treatment

The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.


How is familial adenomatous polyposis diagnosed?

Familial adenomatous polyposis (FAP) is usually diagnosed by checking for the presence of polyps in a patient’s colon. There are several methods that can be used to screen for polyps. Patients who have a family history of FAP are encouraged to undergo screening early on (in their teens) so that polyps can be detected before cancer has a chance to develop.

  • Colonoscopy: Doctors may perform a colonoscopy to check for polyps in the colon. In a colonoscopy, a flexible tube with a light attached (called an endoscope) is inserted through a patient’s anus. The endoscope can transmit images of the patient’s colon to the doctor so that any polyps can be observed.
  • Barium enema: To visualize the entire large intestine, a liquid dye called barium may be used to fill and coat a patient’s intestine. Then, a doctor uses X-rays to take pictures of the patient’s intestine. The barium will cause any polyps along the lining of the intestine to appear as dark areas on the X-ray image, allowing the polyps to be observed.
  • Computed tomography: An imaging technique called a computed tomography (CT) scan may be used to observe polyps in a patient’s colon. A CT scan is a noninvasive imaging technique that uses a series of X-rays to create detailed three-dimensional images of the inside of a patient’s body. Polyps can then be detected in these images.
  • Genetic testing: Mutations in the APC gene or MUTYH gene are known to cause FAP. Genetic tests can be used to check for these mutations and diagnose FAP. These tests may confirm a diagnosis if there is a family history of FAP or if symptoms of FAP are present.


How is familial adenomatous polyposis treated?

If polyps are found at an early stage before cancer has a chance to develop, they can be surgically removed. Patients with familial adenomatous polyposis (FAP) who have polyps removed early in the disease have a very high chance of not developing cancer (near 100%).

There are often too many polyps present to remove each one individually. Depending on the extent of the disease, a patient will need to have the entire colon removed (a colectomy) or the colon, rectum, and in some cases the anus removed (a proctocolectomy).

In a colectomy, the colon is removed, and the small intestine is surgically connected directly to the anus. In a proctocolectomy in which the colon and rectum are removed, a small pouch is inserted to connect the small intestine to the anus and allow the passage of waste. In a proctocolectomy in which the colon, rectum, and anus have been removed, a portion of the intestine may be brought out through a hole in the abdominal wall, so waste can be directly delivered to an external bag.

Patients who undergo surgery need to have frequent checkups (every three to twelve months) to ensure that polyps do not begin to form in other parts of the digestive tract, such as the stomach, upper third of the small intestine (duodenum), or rectum (if it was not initially removed). If new polyps are observed, patients may need to undergo additional surgeries.

In patients who do not have polyps removed promptly and as a result develop cancer, a number of treatments are available to help to control the tumor growth. Tumors may be removed surgically or cancer cells may be killed with radiation or with drugs (such as irinotecan, oxaliplatin, and 5-fluorouracil). Patients who develop cancer should consult with a physician to determine the best therapy. If treated at an early stage, patients who develop colon cancer have a good chance of surviving.

Lifestyle changes & Home remedies

What are some lifestyle changes or home remedies that can help me manage familial adenomatous polyposis?

The following lifestyles and home remedies might help you cope with familial adenomatous polyposis:

Most patients are able to eat normal diets and lead normal lives following surgery. Some people notice more frequent bowel movements. Otherwise, their lives will be perfectly normal. Their sexual and social activities are unaffected. None of the procedures affects a man’s ability to father children nor a woman’s ability to have a normal pregnancy. However, the way in which a baby is delivered may be affected by the type of surgery and should be discussed with the surgeon.


If you have any questions, please consult with your doctor to better understand the best solution for you.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: June 16, 2017 | Last Modified: September 12, 2019