Gastrointestinal (GI) Tests and Exams

A gastrointestinal (GI) test or exam is a procedure healthcare providers use to find problems in your digestive tract. This includes your esophagus, stomach, small intestine, large intestine and rectum. A GI exam can confirm a diagnosis, rule out other causes or help a provider decide what to do next. In many cases, GI exams also let providers avoid more extensive procedures to get to the root of the issue.

Your GI tract is complex. So, your provider will choose the type of test (or combination of tests) that best addresses your symptoms. GI tests typically fall into three categories:

• Imaging tests take pictures of your digestive tract.
• Endoscopy lets your provider look inside your digestive system and, in some cases, take tissue samples.
• Lab and functional tests use samples from blood, breath, poop or tissue to look for signs of infection, inflammation and other GI conditions.

Why would I need a GI exam?

A provider may suggest a GI exam to figure out what’s causing your gastrointestinal symptoms, like:

• Belly pain
• Blood in your poop
• Diarrhea
• Difficulty swallowing
• Acid reflux
• Severe indigestion
• Vomiting

These tests can diagnose many different conditions, such as:

• Barrett’s esophagus
• Chronic acid reflux (GERD)
• Dysphagia
• Enteritis
• Gastritis
• H. pylori infection
• Hiatal hernia
• Inflammatory bowel disease (IBD)
• Irritable bowel syndrome (IBS)
• Polyps
• SIBO
• Stomach flu
• Tumors
• Ulcers

How do I prepare for a GI test?

Depending on the test you’re having, your healthcare provider will give you specific guidelines in the days or weeks leading up to it. Following these instructions keeps you safe and ensures the test results are accurate.

You might be asked to:

• Fast: You’ll stop eating for a specific period of time (usually the night before the test). This helps keep you from getting sick to your stomach and lets your provider see things more clearly.
• Follow a special diet or do bowel prep: You might need a low-fiber or clear liquid diet before your GI test. You may also have to do bowel prep. These methods make your digestive tract easier to look at.
• Stop smoking: Smoking can impact the way you digest.
• Stop taking certain medications: This is only temporary. Some medicines can affect test results or put you at risk of test complications.

Some tests don’t need any preparation at all.

What happens during a GI test?

What happens during your GI test depends on the type you need. Different types of GI tract exams can help providers paint a more complete picture of what’s going on in your specific case. These can involve imaging, endoscopy, or lab and functional tests.

Imaging

Providers prefer to use fluoroscopy when they do imaging to look at your GI tract. With this type of test, you’ll swallow a contrast dye that helps providers see your insides more clearly. Then, a provider will take a real-time video of your organs in action.

Examples of imaging tests with fluoroscopy include:

• Barium swallow test (esophagram)
• Upper GI and small bowel series
• Barium enema (lower bowel series)

Endoscopy

For this type of GI exam, a provider will use a lubricated tube with a light and camera on the end (endoscope) to get a better look at your digestive system.

Examples include:

• Upper endoscopy (EGD): A scope goes through your mouth to look at your esophagus, stomach and the upper portion of your small intestine. You’ll be asleep under anesthesia.
• Colonoscopy: An endoscope goes into your anus (butthole) and up into your colon and large intestine. You can choose to have anesthesia or conscious sedation.
• Anoscopy: A provider uses a scope to examine your anus. You’ll be awake, though you might experience temporary discomfort.
• Sigmoidoscopy: A provider sends the scope through your anus to see the lower part of your colon (sigmoid) and rectum. Typically, you’ll be awake with mild discomfort.
• Proctoscopy: A provider uses a scope to look at your rectum and anus. You’ll probably be awake. Be sure to tell your provider if you feel any pain.

If needed, your provider can also use the endoscope to take a tissue sample (biopsy) during the test. They’ll send the sample to a lab for testing.

These exams can take anywhere from a few minutes to an hour.

Lab and functional tests

Lab and functional tests involve taking samples of tissue, blood or other bodily fluids — like pee (urine) and poop (stool) — to help find the cause of your symptoms. Biopsy falls under this category. Other tests include:

• Stool tests: These use samples from your poop to look for signs of infection, inflammation and GI bleeding.
• Breath tests: These look for certain gases in your breath that bacteria make. Providers use breath tests when they suspect that you have a GI bacterial infection.
• C-reactive protein (CRP) test: This is a blood test that checks your C-reactive protein levels. Your liver makes C-reactive protein and releases it in response to inflammation.

What happens after a GI test?

If you had fluoroscopy, you’ll be encouraged to drink plenty of fluids. This helps get the contrast out of your system. You may have diarrhea or constipation for a day or so, and your poop may be white for the next few days.

If you were sedated for endoscopy, you’ll be moved to a recovery room. Your care team will keep an eye on you until you wake up. You’ll need to have someone drive you home. If you were awake the entire time, you can drive yourself home and go back to your normal routine.

In both cases, you may feel bloated or crampy as air leaves your digestive tract.

If you had a lab or functional test, you can expect to return to your usual activities and eating habits right away.

Risks/Benefits

GI exams are generally safe and effective at finding the cause of your symptoms. Your care team will check on you at every step. But risks might include:

• A tear in your GI tract
• Abnormal reactions to anesthesia
• GI bleeding from a biopsy
• Infection
• Contrast-associated acute kidney injury (this is rare)
• Radiation exposure (from some imaging tests, but the risk is very low)

In general, the benefits of GI tests are that they help your healthcare provider find the cause of your symptoms. That way, your provider can make sure your treatment plan works for you.

When can I expect to know the results of my GI test?

The kind of test you have will determine when you get your results. Your provider might tell you the results right after. Or it may take several days for results to come back. When they do, your provider will review them and discuss any additional testing, treatment or follow-up, if needed.