An enteroscopy is a procedure that examines the small intestine, the long middle section of your digestive tract that standard upper endoscopy and colonoscopy can’t fully reach. A doctor threads a long, flexible tube with a camera and a balloon system through either the mouth or the rectum, advancing it deep into the small bowel to find and sometimes treat problems like unexplained bleeding, polyps, or narrowed passages.
Why the Small Intestine Needs Its Own Procedure
Your small intestine is roughly 20 feet long, coiled tightly in your abdomen. A standard upper endoscopy only reaches the first portion, and a colonoscopy can typically get to the very end of it (the ileum) from the other direction. That leaves a large middle stretch that neither procedure can see. Enteroscopy was developed specifically to close that gap.
The most common reason doctors order an enteroscopy is obscure gastrointestinal bleeding, meaning bleeding that showed up on lab work or symptoms but couldn’t be located with a standard scope from either end. The diagnosis rate for unexplained bleeding during enteroscopy is about 81%. It’s also used to investigate suspected Crohn’s disease in the small bowel, evaluate abnormal findings from imaging, look for tumors or polyps, and dilate narrowed sections of intestine.
Types of Enteroscopy
Several techniques exist, and the choice depends on where the problem is suspected and what the doctor may need to do once inside.
Balloon-Assisted Enteroscopy
This is the most widely used approach. The scope has one or two inflatable balloons near its tip. The doctor alternately inflates and deflates these balloons to “accordion” the intestine over the tube, allowing the scope to travel much deeper than a standard endoscope could. Double-balloon enteroscopy (using two balloons) and single-balloon enteroscopy (using one) have similar diagnostic success rates. In a large multicenter study of nearly 2,900 single-balloon procedures, the major complication rate was just 0.4%, all involving intestinal perforation identified during the procedure. No cases of pancreatitis or significant bleeding were reported.
Spiral Enteroscopy
Instead of balloons, this technique uses a rotating spiral overtube that threads the intestine onto the scope, similar to a corkscrew. A newer motorized version shortens procedure time compared to balloon methods and reaches deeper into the small bowel. Overall diagnostic and therapeutic success rates are comparable to balloon-assisted approaches.
Capsule Endoscopy
While not technically an enteroscopy, capsule endoscopy is often discussed alongside it. You swallow a pill-sized camera that takes thousands of photos as it travels through your digestive tract. It’s excellent for spotting surface-level problems like mucosal bleeding sources, but it can’t take tissue samples or treat anything it finds. Doctors often use capsule endoscopy first as a screening step. If something abnormal appears, or if the capsule study is negative but symptoms persist, a balloon or spiral enteroscopy follows to biopsy or treat the area directly.
What Doctors Can Do During the Procedure
One of the biggest advantages of enteroscopy over capsule endoscopy is that it’s not just diagnostic. During the same session, a doctor can take tissue biopsies from suspicious areas, remove polyps, cauterize bleeding blood vessels, dilate narrowed sections of bowel (common in Crohn’s disease), remove foreign objects, and place stents. For patients with conditions like Peutz-Jeghers syndrome, where polyps grow repeatedly in the small intestine, enteroscopic removal can sometimes prevent the need for surgery. The thin wall of the small intestine does make these interventions more delicate than similar work in the colon, so doctors typically inject fluid beneath polyps before removing them to reduce the risk of perforation or bleeding.
How to Prepare
Preparation depends on whether the scope enters through the mouth (antegrade) or the rectum (retrograde). For an upper approach, you’ll typically fast for at least 8 to 12 hours beforehand, sticking to clear liquids the day before. For a lower approach, the prep looks more like a colonoscopy: a clear liquid diet for the full day before, followed by a bowel-cleansing solution you drink in two rounds, once the evening before and once the morning of the procedure. The goal is to clear out your intestines so the camera has an unobstructed view.
You’ll also need to stop certain supplements like iron and fiber powder about a week beforehand, since they can interfere with visibility. Your care team will give you specific instructions about any medications you take, particularly blood thinners.
What Happens During the Procedure
You’ll receive sedation, typically through an IV, so you won’t be awake during the procedure. The doctor inserts the enteroscope and advances it through the small intestine section by section, using the balloon or spiral mechanism to gather the bowel onto the tube. Real-time video from the camera tip appears on a monitor, letting the team inspect the lining and perform any needed interventions.
The whole process can take up to several hours depending on how far the scope needs to travel and whether any treatments are performed. A purely diagnostic pass is generally shorter than one involving polyp removal or cauterization.
Recovery and Side Effects
After the procedure, you’ll spend some time in a recovery area as the sedation wears off. Common side effects are mild: bloating, gas, cramping, and a sore throat if the scope went in through the mouth. These typically resolve within a day.
Because sedation affects your reaction time and judgment even after you feel alert, you won’t be able to drive yourself home. Plan to take it easy for the rest of the day, and avoid making important decisions for 24 hours. Most people return to normal activities the following day, though your doctor may give different guidance if a therapeutic intervention was performed during the session.