Crohn’s Disease Diagnosis: What to Expect

Medically Reviewed By Kelsey Trull, PA-C
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Crohn’s disease is a long-term inflammatory bowel disease (IBD) that causes fatigue, diarrhea, stomach cramps, and weight loss. The disease is often challenging to diagnose because the symptoms are similar to other conditions. The Centers for Disease Control and Prevention (CDC) estimates that Crohn’s disease, or ulcerative colitis, affects about 3 million U.S. adults. Most people receive a diagnosis between ages 15-35. 

A doctor can evaluate your symptoms and order tests to help them diagnose Crohn’s disease. Tests include:

  • blood
  • stool
  • imaging

Initial evaluation and testing

A doctor and a patient are talking
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The National Health Service (NHS) recommends seeing a doctor if you have frequent stomach aches or diarrhea that lasts more than 7 days. 

The National Institute of Diabetes and Digestive Kidney Diseases (NIDDK) states that during a physical exam, a doctor can check you for abdominal bloating and tenderness. They may also tap on your abdomen to check whether you have an enlarged liver or spleen. 

According to a 2017 study, you may be at risk of developing liver problems if you have Crohn’s disease. Symptoms may include bleeding easily, abdominal pain, or jaundice

Consider the following before the first visit with a physician:

  • the number of times you or your child have visited the bathroom
  • whether you or your child are taking any medications
  • whether you or your child have any allergies
  • whether you need a doctor’s note for your child’s school indicating they have Crohn’s disease cramps

Crohn’s disease has no single test. However, the following can help your doctor reach a diagnosis.

Blood test

Blood tests can indicate whether you have anemia or inflammation in the body. Anemia occurs when your body has low levels of red blood cells. Anemia affects about 1 in 3 people with Crohn’s disease. 

Also, according to the NIDDK, if your blood test indicates a high white blood cell count, you may have inflammation or an infection. 

Stool test

Healthcare professionals may need a stool sample to test for bleeding and inflammation. There are many types of stool studies to rule out infection, check for blood, and look for biomarkers such as calprotectin.

If the calprotectin level is high, you may need further testing for Crohn’s disease. Calprotectin can also be high if you have gastroenteritis, another term for stomach flu. It can cause diarrhea, vomiting, and fever

CT scan

A CT scan uses X-ray and computer technology to create three-dimensional images of your digestive tract. 

Before the exam, you may have to drink a special dye that makes it easier for your doctor to look for blockages, infections, and other complications. 

MRI scan

During an MRI scan, you lie inside a long tube that uses strong magnets and radio waves to produce images of your internal organs. 

You may have to drink a contrast material to help physicians examine the detailed images. 

MRI scanners can be loud, so consider wearing earplugs during the exam. 

Medical professionals may not recommend MRI exams if you have a pacemaker or metal artificial joints. 


Intestinal endoscopy can help doctors diagnose Crohn’s disease and check that you do not have cancer or other digestive diseases

These are the types of endoscopies that can be helpful for diagnosis:


A colonoscopy involves inserting a colonoscope into the rectum and going into the colon. The device is known as a colonoscope or endoscope. It’s a long tube with a camera on one end. 

It helps doctors examine your rectum and colon. It can be beneficial for those who have blood in their stool, persistent constipation, diarrhea, or anemia.

The medical team will tell you what you can eat and drink days before the procedure. They may also give you laxatives, which will help you empty your bowel before the appointment. 

Upper GI endoscopy

An upper gastrointestinal (GI) endoscopy allows a close look at your GI tract. 

You may have to fast before undergoing an upper GI endoscopy. You may also have to drink a liquid anesthetic to numb your throat. You will usually undergo sedation during this procedure.

Capsule endoscopy

If you undergo a capsule endoscopy, you may have to swallow a capsule that contains a camera, light, and transmitter. It goes to your digestive system and transmits images to a monitoring device the physician asks you to wear. 

The camera should leave the body during bowel movement. 

Balloon assisted enteroscopy

Sometimes, medical professionals may perform balloon enteroscopy procedures. 

They insert an endoscope with two balloons at the tip through the mouth or anus. The balloons help the device move around the small intestine. The device may also be helpful for those having a biopsy or polyps removed.

Learn how to prepare for an endoscopy.

Upper GI series

An upper GI series is an imaging test that uses X-rays to view the individual’s upper GI tract. It also involves drinking barium liquid, making the internal organs more visible on X-ray images. 

You may be the right candidate for this test if you have:

  • swallowing difficulties
  • abdominal pain
  • nausea and vomiting
  • prior abdominal surgeries 

An upper GI series can determine the cause of your symptoms. 

Some people may develop constipation, intestinal obstruction, or an allergic reaction from barium. Call your doctor right away if you have a fever, severe abdominal pain, or cannot pass gas after your procedure. 


During a biopsy, the clinician examines a tissue sample from your intestines under a microscope. It usually includes healthy and inflamed tissues. 

The biopsy usually takes place during other procedures, such as a colonoscopy and upper endoscopy.  


Chromoendoscopy is a procedure in which healthcare professionals spray a special dye onto the bowel lining. It helps distinguish between inflamed areas or those of concern and unaffected tissue. 

It allows doctors to see how the areas react to the substance. They may also perform a biopsy to look at the tissue under a microscope.


Learn more about treatment for Crohn’s disease:


Crohn’s disease is an inflammatory bowel condition that causes swelling and inflammation in your digestive tract. 

You may experience pain, rectal bleeding, or unexplained weight loss

There is no single test to diagnose Crohn’s disease. Medical professionals perform different lab tests and procedures to check for inflammation in your digestive tract. 

These include blood tests, CT scans, endoscopies, or biopsies. 

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Medical Reviewer: Kelsey Trull, PA-C
Last Review Date: 2023 Jan 17
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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