Endoscopy in Crohn's Disease

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Facts about endoscopy in diagnosing Crohn's disease

  • There is no simple lab test that allows a definitive diagnosis of Crohn's disease. If a person has symptoms suggesting inflammatory bowel disease (Crohn's disease or ulcerative colitis), their primary health-care professional or gastroenterologist will probably recommend endoscopy ("scope").
  • Endoscopy is a test in which a thin tube with a light and a tiny camera at the end is inserted into your digestive tract. The camera transmits pictures back to a video monitor, where they are magnified so the doctor can see exactly what the inside of the digestive tract looks like.
  • The endoscope shows ulcers, bleeding, and other signs of Crohn's disease and indicates the location and extent of the disease within the digestive tract.
  • With endoscopy, the doctor can tell whether a person has Crohn's disease or a similar condition called ulcerative colitis (or some other condition).
  • Ulcerative colitis, like Crohn's disease, affects one section of the large intestine (colon) only, while Crohn's disease is more likely to affect the small intestine and often attacks different parts of the digestive tract with normal tissue in between ("skip lesions").
  • Symptoms of Crohn's disease depend upon the part of the digestive tract affected; but may include:
  • Endoscopy allows the doctor to not only see the inside of the digestive tract, but also to take small samples (biopsies) of tissue for further examination under a microscope. This can help confirm the diagnosis and show the extent of Crohn's disease.

Crohn's Disease: Symptoms, Causes and Treatment

Is the endoscopy procedure painful?

While endoscopy is not usually painful, it can be uncomfortable, and many people feel apprehensive. If a patient is having an EGD, ERCP, or colonoscopy, they will probably be given a pain medication and a sedative to relax for the procedure. Patients should arrange for someone else to pick them up and drive them home after the test. Sigmoidoscopy is a limited test and does not usually require sedation.

What are other names for endoscopy in diagnosing Crohn's disease?

Doctors have different names for endoscopy depending on which part of the digestive tract they are examining.

  • Esophagogastroduodenoscopy (EGD): Also called upper endoscopy, this test examines the lining of the esophagus (the tube between the mouth and stomach), the stomach, and the duodenum (the upper part of the small intestine).
  • Colonoscopy: This test examines the lining of the colon, or large intestine, and sometimes the lower part of the ileum (the lowest part of the small intestine).
  • Sigmoidoscopy: This test examines the lining of the lowest third of the colon, which includes the rectum. The name of the test derives from a bend called the sigmoid in this part of the colon.
  • Endoscopic retrograde cholangiopancreatography (ERCP): This test combines endoscopy with X-rays to examine the ducts that open into the small intestine from the liver, gallbladder, and pancreas. In some people with Crohn's disease, these ducts become inflamed and close up.
  • Endoscopic ultrasound: This test combines endoscopy with ultrasound, a technology that uses sound waves to create images of organs deep within the body. (This is the same safe technology used to look at a fetus in its mother's womb.) This technique is widely used in the United States to evaluate fistulas, a common complication of inflammatory bowel disease.
  • Balloon endoscopy, or enteroscopy is an endoscopic procedure that allows the physician to visualize the entire small intestine and take tissue biopsies.
  • Capsule endoscopy (wireless endoscopy) is an endoscopic procedure in which a small video capsule is swallowed by the patient. The video capsule takes photographs of the inside of the esophagus, stomach, and small intestine. The drawbacks of capsule endoscopy include: 1) areas missed due to the rapid transit of the capsule, 2) battery failure, 3) inability to take tissue biopsies, 4) the capsule becoming stuck or lodged in strictures or tumors, and 5) the camera takes tens of thousands of photographs that becomes very time consuming for the health care professional to review.
  • Barium X-rays: These may include a barium swallow (upper GI series) or a barium enema (lower GI series).

Which of these tests your doctor chooses to do depends on the symptoms the patient has. Generally, the patient's symptoms suggest what part of the digestive tract is involved.

Crohn's Disease Symptoms

Signs and symptoms of Crohn's disease depends on the area of the digestive tract that is affected; however, may include:

  • Diarrhea that waxes and wanes, and the stool may contain pus, mucus, or blood
  • Pain in the lower right part of the abdomen or around the belly button that is crampy or steady
  • Constipation
  • Pain or bleeding with bowel movement
  • Low-grade fevers

How do I prepare for the endoscopy procedure?

The results of endoscopic tests are useful only if the patient follow their doctor's instructions to prepare before the test. The preparations involve clearing as much stool and food residue out of the digestive tract as possible, since this material can hide signs of disease. The "bowel prep" regimen varies slightly among the different tests.

  • EGD: Generally the only preparation is taking no food or beverages after midnight the night before the test and until the test is completed.
  • ERCP: The preparation for ERCP is the same as for EGD.
  • Colonoscopy: The entire colon should be as clean as possible. Patients should follow the instructions given by their doctor exactly. Patients may be asked to avoid solid foods for a day or two before the test. Patients will asked to not eat or drink anything after midnight the night before the test. There are several options available to clean the bowel. A few of these include plyethylene glycol solution (GoLYTELY, NuLYTELY, CoLyte) and Fleet Phospho-Soda liquid. Your physician will have recommendations for which bowel prep to use.
  • Sigmoidoscopy: Patients use enema solutions the night before and the morning of the test to clear all stool from the lower colon.

What happens during endoscopy?

During the test, the patient will lie down on an adjustable stretcher. The position will depend on the test being performed, and the techniques of the doctor performing the test. If the patient is sedated, your blood pressure and blood oxygen will be monitored.

How long does endoscopy last?

The procedure will take anywhere from about 10 to about 30 minutes, depending on the test being performed. If the patient has been sedated, they will be taken to a recovery room and monitored by nurses until they are alert enough to leave.

What are the complications of endoscopy?

Endoscopy is a very safe procedure. Like all procedures, however, it carries some risks. Complications are very rare, but they can be serious. The instrument can cause a small hole in the intestinal wall. This is called perforation. The risk of this is less than 1 in 1000. Other risks are bleeding and infection.

Before the test, patients will be asked to read and sign an informed consent. Patients should make sure they understand why the test is necessary and what the risks are. Ask the doctor if there are any questions.

Reviewed on 6/27/2016

Medically reviewed by John A. Daller, MD; American Board of Surgery with subspecialty certification in surgical critical care


Kita, H., MD. "Overview of deep small bowel enteroscopy." UpToDate. Updated Jul 15, 2015.

Peralta, R., MD. "Capsule Endoscopy." Medscape. Updated Dec 04, 2016.

Stein, D. E., MD. "Colonoscopy." Medscape. Updated Mar 13, 2016.

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