What Is Capsule Endoscopy?

What to expect when undergoing this test

camera in pill capsule
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Capsule endoscopy is a diagnostic procedure in which you swallow a capsule-encased micro-camera so that images of your esophagus, stomach, and small intestine can be taken as the device pass through your gastrointestinal (GI) tract. Traditionally, doctors have used endoscopy—a procedure in which a flexible scope is inserted down your throat—to diagnose upper GI disorders. But capsule endoscopy has gained favor as it is painless, minimally invasive, and doesn’t require anesthesia. Moreover, it allows the doctor to visualize the entire length of the small intestine, not just the first one to two feet.

Purpose of Test

Capsule endoscopy is used to examine parts of the GI tract that cannot be seen with other types of endoscopy. 

The disposable capsule, often referred to as a "pill-cam," is roughly the size of a large vitamin tablet, allowing it to navigate your GI tract better than a scope. Within the self-contained unit is a miniaturized video camera programmed to take between two and 18 images per second, which then ultimately get transmitted to sensor equipment. (A regular video camera shoots between 24 and 25 images per second.) Also housed within the unit is one or several tiny LED lights, a radio transmitter, and an eight-hour power source.

This test is typically used when a disease is suspected in the small intestine or to pinpoint the location of bleeding, inflammation, or damage.

Among some of the reasons why capsule endoscopy may be used:

Capsule endoscopy is typically used to investigate blood loss only after endoscopy or colonoscopy fail to reveal the source of the bleed. Around 5 percent of unexplained bleeding episodes stem from the small intestines, most often from small vascular lesions known as angioectasias.

Unlike endoscopy or colonoscopy, which can be used to remove polyps (polypectomy), capsule endoscopy can only be used for visual diagnoses, not treatment.

Accuracy

The accuracy of capsule endoscopy can vary by the aim of the investigation and the device used. (There are currently three capsule endoscopy systems approved by the U.S. Food and Drug Administration.) According to a 2015 study from University Hospital Ghent in Belgium, capsule endoscopy can correctly diagnose active bleeding in the small intestine in around 58 percent to 93 percent of cases.

When used to diagnose Crohn's disease, capsule endoscopic is considered superior at detecting early inflammatory lesions compared to all other modalities. It is 26 percent more accurate than an X-ray, 16 percent more accurate than a barium study, 25 percent more accurate than colonoscopy, and 21 percent more accurate than a computed tomography (CT) scan.

Similarly, capsule endoscopy is between 83 percent and 89 percent accurate in correctly detecting celiac disease, although a biopsy is still needed for a definitive diagnosis.

However, because the camera is simply swallowed and allowed to make its way through your system on its own, this visualization technique is passive. Even if the procedure is more likely to spot an intestinal disorder, the image may be fleeting or obscured, which can affect the conclusions that can be drawn from the test.

Risks and Contraindications

Capsule endoscopy is considered a safe method of directly diagnosing bleeding and other GI disorders not identified by indirect means.

There is a chance, albeit slight, that the capsule can get "stuck" in the digestive tract (such as in an intestinal pocket caused by diverticular disease).

There is also a risk of bleeding, particularly if the capsule passes through a narrowed passage (stricture) where there is inflammation or tissue damage.

While bowel obstruction is rare with capsule endoscopy, an emollient purgative like polypropylene glycol may be used to ease the passage of the capsule if needed. Less commonly, a procedure known as double-balloon enteroscopy (in which two balloons alternately inflate and deflate) can gently compel the capsule past the site of obstruction. In rare cases, surgery may be required.

Capsule endoscopy is contraindicated in people with a known bowel obstruction. It should be used with caution in anyone who is at risk of an obstruction, including those with a swallowing disorder (dysphagia); who is pregnant; or who has a pacemaker or other implanted cardiac device.

Before the Test

Capsule endoscopy does not require anesthesia. That said, it requires many of the same preparations used for a traditional endoscopic procedure.

Timing

The capsule endoscopy procedure requires overnight fasting and, as such, is always scheduled first thing in the morning. After the sensor equipment is applied and the pill-cam in swallowed, the imaging will continue automatically as you go about your day. The test is complete when you either evacuate the pill-cam in stool or after eight hours, whichever comes first.

Location

Capsule endoscopy can be performed at a gastroenterologist office, a gastroenterology procedure unit of a hospital, or an independent endoscopy center available in some cities.

What to Wear

Eight adhesive sensors will need to be placed on parts of your abdomen. To reduce sweat and make application easier, wear a light, untucked cotton T-shirt. As the sensors will transmit to a sensor belt or data recorder that you must wear around your waist (if not over your shoulder with a holster), choose a shirt that is long enough to reach at least hip level and will not ride up. Your outfit should be one you won't need to change out of for at least eight hours, as the equipment must remain in place until the test is over.

Food and Drink

You will need to stop eating and drinking at least 12 hours before the procedure. This helps improve the image quality as the pill-cam makes its way through the digestive tract.

Generally speaking, you will need to stop eating solid food at around noon the day before the test. Until 10:00 p.m., you can consume liquids, such as water, coffee, tea broth, clear broth, clear soda, and gelatin. Avoid milk or any liquid or gelatin that is red or purple (this may register on camera as blood).

Some doctors may instruct you to take 10 fluid ounces of magnesium citrate at 7:00 p.m. The over-the-counter product can help gently clear stools from the body. Be sure to get the light-colored (lemon-lime) formulation, rather the red (cherry-flavored) one.

From 10:00 p.m. until the time you swallow the pill-cam the next day, you will need to stop all fluids, including water. Other food restrictions should continue for the duration of the test.

Medications

Some medications will also need to be stopped before the capsule endoscopy procedure. Chief among these are iron supplements or any multivitamins containing iron. Iron can not only stain the walls of the intestines; it can make it far more difficult to pass the capsule.

As such, you will need to stop taking iron-containing supplements three to four days before the test. You may also be advised to avoid strenuous exercise a day in advance as it may slow peristalsis, the rhythmic contraction of gastrointestinal tissue.

Pepto-Bismol (bismuth subsalicylate) should also be stopped three or four days in advance because it can also affect peristalsis and leave black-colored deposits.

While blood thinners and aspirin are typically avoided prior to traditional endoscopy (due to the risk of bleeding), they pose no such risk for capsule endoscopy.

Finally, if you take chronic medications, you may need to delay doses until two hours after the pill-cam is swallowed. Speak with your doctor to make the appropriate adjustments so that you don't entirely miss your daily dose.

What to Bring

Be sure to bring your ID and health insurance card to your appointment. If you have to delay a medication dose and are not planning to return home after the test is started, be sure to bring the dose with you.

Cost and Health Insurance

Depending on where you live, capsule endoscopy can cost anywhere from $1,000 to $2,000. That still represents a savings of $750 to $1,000 compared to traditional endoscopy.

Insurance pre-authorization is required for the test. Ultimately, the decision to authorize is based on the prescribed treatment guidelines and the associated ICD-10 diagnostic code. In some cases, capsule endoscopy may only be approved after traditional endoscopy has been performed.

Call your health insurance representative to understand what the guidelines dictate. If the procedure is denied, your doctor may be able to provide additional motivation as to why the procedure to essential. Unfortunately, cost savings is not usually a motivating factor.

If you are uninsured or cannot afford the copay or coinsurance costs, shop around for the best price. Independent endoscopy centers may offer nominal savings. Ask if there are monthly payment options or a discount if the payment is made up front.

Other Considerations

If you are especially hairy, you may be asked to shave parts of your chest and abdomen in order to affix the sensors. Doing so in advance will save you time at the doctor's office.

Though the equipment can be bulky and cumbersome, some people choose to work or continue their normal daily routine during the test. Others stay home. While the belt and data recorder are portable, they are not invisible.

During the Test

Capsule endoscopy is a relatively straightforward procedure. The preparation takes place in the doctor's office or a procedure center. The remainder of the test continues as you go about your day.

Pre-Test

After signing in with your ID and health insurance information, you will be led to the procedure room by a doctor or endoscopic technician. You will remove your shirt and the sensors—each containing an antenna and long wires—will be applied. The sensor belt will be strapped around your waist over your shirt; if a separate recording device is being used, it will be slung over your shoulder with a strap. The wires will then be attached to whichever unit was provided. You can then replace your shirt.

Once all the equipment is in place and checked out, you will swallow the pill-cam with a little water. (Its slippery outer coating helps it go down easy.) You shouldn't be able to feel the pill-cam from then on.

All told, the preparations will take around 15 minutes, barring delays. You are then free to leave office, drive, and even return to work if appropriate. You must avoid strenuous physical activity and follow specific dietary guidelines throughout the day.

Throughout the Test

The actual imaging starts the moment you swallow the pill cam. The camera will "telecast" the images it takes to the sensors, and the signals will be delivered to the sensor belt or recording device (either wirelessly or via cables).

While instructions can vary, you will generally be able to resume any medications two hours into the test. You will also be allowed to consume clear liquids, including broth or a light-colored sports drink. After four hours, you will usually be permitted to have a light lunch or at least a snack. After that, your doctor will ask you to continue a liquid diet until you either see the pill-cam in the toilet after a bowel movement or reach the eight-hour mark. When that happens, the test is over.

Post-Test

The pill-cam is disposable and can be flushed down the toilet. You can then remove the patches, belt, and data recorder.

You can return to your normal routine and diet unless your doctor tells you otherwise. The morning after your test is done, you will need to return the equipment to the doctor's office so that the images can be downloaded and reviewed by a gastroenterologist. The test results are usually available within a week.

After the Test

It may take some people hours or days to evacuate the pill-cam; most people pass it in 24 to 72 hours. If you unable to spot the pill-cam in your stools after two weeks, call your doctor. An X-ray may be needed to see if the device is stuck somewhere in your digestive tract.

Some people may experience constipation after the procedure, which usually resolves within a couple of days. To help normalize your bowel movements, drink plenty of fluids and increase your intake of insoluble fiber. If needed, speak with your doctor about an over-the-counter laxative or stool softener if constipation persists.

While bowel obstruction or injury is rare, call your doctor if you experience any abdominal pain, bleeding, fever, bloating, or are unable to pass gas.

Interpreting the Results

A capsule endoscopy report is more or less the same as a traditional endoscopic report. The report will contain a list of normal and abnormal findings, along with preliminary interpretations.

It will also include details about bowel preparation, the quality of bowel preparation, the extent and completeness of the exam, relevant findings, and so-called "pertinent negatives" (expected findings that the patient denies having).

While some findings can be readily observed, such as bleeding or strictures, others may be ambiguous.

On its own, capsule endoscopy is not inherently diagnostic, but it can often be used in tandem with other evaluations to reach a definitive diagnosis. If a conclusive diagnosis is not achieved, additional evaluation or review of your results by other specialists may be needed.

Follow-Up

Follow-up may be needed if there are any abnormal findings. While some, like bleeding or an obstruction, can be used to direct treatment, others may require further investigation given the limitation of what a visual image can confirm.

One such example is the detection of polyps during the procedure. While certain characteristics of a polyp may be suggestive of cancer (including a larger size and increased vascularity), an endoscopic procedure called esophagogastroduodenoscopy (EGD) may be needed to remove and definitively diagnose the growth in the lab. On the other hand, growths that are consistent with cancer (including bleeding, growth clusters, and an irregular, non-capsulated structure) may require laparoscopic or open surgery.

Similarly, while some disorders like celiac disease may be treated presumptively based on the visual findings, many doctors will insist on obtaining a tissue sample so that the disease can be typed and treated appropriately.

In some cases, the test may need to be repeated to obtain better images, particularly if symptoms persist despite a negative result. A retrospective study conducted in 2010, which evaluated 82 people who had undergone more than one capsule endoscopic procedure, concluded that a repeat test yielded a change in treatment in 39 percent of cases. Moreover, nearly half of the people who had an incomplete first test (10 out of 22) had an abnormal finding in the second.

A Word From Verywell

As valuable a tool as capsule endoscopy is, it is not infallible. A test can easily be compromised if you don’t follow the bowel preparation and dietary instructions. Technical glitches can also occur, affecting as many as 8.5 percent of all procedures, according to a study from the University of British Columbia in Canada.

If the equipment malfunctions, ask for a copy of the endoscopic report and advise your health insurer so that you won’t be double-billed when the test is repeated.

If the test uncovers no unusual findings but you still have symptoms, don’t hesitate to seek a second opinion. Sometimes having another set of eyes will bring new insights to the investigation. You can usually ask for the report to be forwarded electronically, ideally with the complete video footage in a digital format. 

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