Diseases and Conditions

Familial adenomatous polyposis

Diagnosis

You're at risk of familial adenomatous polyposis if you have a parent, child, brother or sister with the condition. If you're at risk, it's important to be screened frequently, starting in childhood. Annual exams can detect the growth of polyps before they become cancerous.

Screening

  • Sigmoidoscopy. A flexible tube is inserted into your rectum to inspect the rectum and sigmoid — the last two feet of the colon. For people with a genetic diagnosis of FAP or family members at risk who haven't had genetic testing, the American College of Gastroenterology recommends annual sigmoidoscopy, beginning at ages 10 to12 years.
  • Colonoscopy. A flexible tube is inserted into your rectum to inspect the entire colon. Once polyps are found in your colon, you need to have an annual colonoscopy until you have surgery to remove your colon.
  • Esophagogastroduodenoscopy (EGD) and side-viewing duodenoscopy. Two types of scopes are used to inspect your esophagus, stomach and upper part of the small intestine (duodenum and ampulla). The doctor may remove a small tissue sample (biopsy) for further study.
  • CT or MRI. Imaging of the abdomen and pelvis may be used, especially to evaluate desmoid tumors.

Genetic testing

A simple blood test can determine if you carry the abnormal gene that causes FAP. Genetic testing may also detect whether you're at risk of complications of FAP. Your doctor may suggest genetic testing if:

  • You have family members with FAP
  • You have some, but not all, of the signs of FAP

Ruling out FAP spares at-risk children years of screening and emotional distress. For children who do carry the gene, appropriate screening and treatment greatly reduce the risk of cancer.

Additional tests

Your doctor may recommend thyroid exams and other tests to detect other medical problems that can occur if you have FAP.