Enteroscopy is a procedure used to examine the small intestine (small bowel).

A thin, flexible tube (endoscope) is inserted through the mouth or nose and into the upper gastrointestinal tract. During a double-balloon enteroscopy, balloons attached to the endoscope can be inflated to allow the doctor to view the entire small bowel.

In a colonoscopy, a flexible tube is inserted through your rectum, through the colon, and into the end part of the small intestine.

Tissue samples removed during enteroscopy are sent to the laboratory for examination.

Do not take products containing aspirin for one week before the procedure. If you take blood thinners such as coumadin (Warfarin), ask your doctor about stopping them as well.

Do not eat any solid foods or milk products after midnight the day of your procedure. You may have clear liquids until 4 hours before your exam. You must sign a consent form.

For infants and children, the preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

• Infant test or procedure preparation (birth - 1 year)
• Toddler test or procedure preparation (1 - 3 years)
• Preschooler test or procedure preparation (3 - years)
• Schoolage test or procedure preparation (6 - 12 years)
• Adolescent test or procedure preparation (12 - 18 years)

When the tube is put into your mouth and down your food pipe, you may feel like gagging. You will get a numbing medicine to reduce this feeling.

You may get a mild sedative, but only in small doses because you must stay alert enough to help with the procedure (by doing such things as swallowing and turning). The biopsy sampling causes little or no pain, although you may have some mild cramping.

This test is most often performed to help diagnose diseases of the small intestines. It may be done if you have:

• Abnormal x-ray results
• Tumors in the small intestines
• Unexplained diarrhea
• Unexplained gastrointestinal bleeding

In a normal test result, the health care provider will not find sources of bleeding in the small bowel, and will not find any tumors or other abnormal tissue.

Abnormal findings may include:

• Abnormalities of the tissue lining the small intestine (mucosa) or the tiny, finger-like projections on the surface of the small intestine (villi)
• Immune cells called PAS-positive macrophages
• Polyps
• Radiation enteritis
• Swollen or enlarged lymph nodes or lymphatic vessels
• Ulcers

Changes found on enteroscopy may be signs of disorders and conditions including:

• Amyloidosis
• Celiac sprue
• Coccidiosis
• Crohn's disease
• Folate or vitamin B12 deficiency
• Giardiasis
• Infectious gastroenteritis
• Lymphangiectasia
• Lymphoma
• Malnutrition
• Tropical sprue
• Whipple's disease

The test may also be performed for lactose intolerance.

Complications are rare but may include:

• Excessive bleeding from the biopsy site
• Hole in the bowel (bowel perforation)
• Infection of the biopsy site leading to bacteremia
• Vomiting, followed by aspiration into the lungs

Factors that prohibit use of this test may include:

• Uncooperative or confused patients
• Untreated blood clotting (coagulation) disorders
• Use of aspirin or other medicines that prevent the blood from clotting normally (anticoagulants)

The greatest risk is bleeding. Signs include:

• Abdominal pain
• Blood in the stools
• Vomiting blood

Sidhu R, Sanders DS, Morris AJ, McAlindon ME. Guidelines on small bowel enteroscopy and capsule endoscopy in adults. Gut. 2008;57:125-136.