Crohn’s disease is a type of inflammatory bowel disease (IBD) that can cause inflammation and ulcers inside a person’s gastrointestinal tract (gut). It usually impacts a person’s small intestine or the start of their large intestine, but can affect any part of the digestive tract from the mouth to the anus.

Crohn’s disease is a chronic illness, which means that it is long term. People may experience symptoms in flare-ups, and may also experience periods of remission when they have no symptoms at all. There is no cure for Crohn’s disease, but treatment can often allow people to live typical lives with long-term relief from symptoms.

Healthcare professionals may conduct a number of tests or procedures to determine if a person has Crohn’s disease. These may include:

  • lab tests
  • imaging tests
  • procedures

This article will explain who may be more likely to get Crohn’s disease and how old they are likely to be. It will explain the different tests doctors may order and what a person can expect during this process.

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According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Crohn’s disease can occur in people of all ages, but it is more likely to happen in people who:

  • are between 20–29 years old
  • have a close family member who also has IBD, such as a parent or sibling
  • smoke

Learn more about the average age a person receives Crohn’s diagnosis here.

Doctors will ask a person about symptoms they have been experiencing. This is an important part of diagnosis and may be one of the first questions a doctor asks.

The signs and symptoms a person should look out for if they suspect that they may have Crohn’s disease include:

Other, less common symptoms of Crohn’s disease may include:

A doctor may require certain tests to diagnose Crohn’s disease. They include blood tests and stool tests.

Blood tests

Healthcare professionals may order a blood test to look for anemia, inflammation, or infection in the body. If they find fewer red blood cells than expected in the body, a person may have anemia. If a person’s white blood cell count is higher than typical, this may be a sign of infection or inflammation.

Stool tests

Testing a person’s feces can allow healthcare professionals to locate any pathogenic bacteria and specific markers of inflammation. It can also help rule out any other causes of digestive discomfort.

Various types of imaging tests can help healthcare professionals to see other details of the digestive system and diagnose Crohn’s disease more effectively.

MRI scans

MRI scans use a combination of radio waves and strong magnetic fields to look inside the body and form images. A person lies on a moveable table that will slowly slide into the tunnel-shaped MRI machine.

MRIs do not use X-ray radiation, so they may be more suitable for people already exposed to high levels of radiation. Sometimes, people may need to drink or receive an injection of a contrast material to allow the MRI to produce more clear and detailed images. This is called an MR enterography scan.

People may be offered ear protection due to the loud nature of the machinery. Since the scans use magnets, MRI scans may not be suitable for everyone, including people with pacemakers and those with metal artificial joints. They also can take 15 minutes to over 90 minutes and can cause people to feel claustrophobic. With MRI scans of the abdomen, however, it is likely that a person’s head may not need to be inside the scanner for the full duration of the scan.

CT scans

A CT scan uses a combination of computer technology and X-rays to gather cross-sectional images of a person’s digestive tract. Healthcare professionals combine these images to create a two-dimensional view of the body. Sometimes they may form three-dimensional views.

CT scans only take approximately 10 minutes to complete, so may be more suitable for children. Not only are CT scans quicker than MRI scans, but they do not involve surrounding the entire body at once, so may also be more appropriate for people with claustrophobia.

Some people may need to receive a dose of contrast dye orally or via an injection to help images of the bowels show up more clearly.

Learn the difference between CT and MRI scans here.

Small intestine imaging

Sometimes, there are areas of the intestine that do not show up clearly with other types of imaging tests. In these cases, doctors may recommend small intestine imaging.

A person swallows a small camera about the size of a pill. The camera takes photos of its journey through the gastrointestinal tract, and the person collects it during a bowel movement.

As well as scans and tests, there are certain procedures that healthcare professionals may order to help accurately diagnose Crohn’s disease.


An endoscopy uses a thin, flexible tube with a light and video camera attached to the end of it. A doctor may thread this through a person’s mouth and down into the stomach to look at the upper part of the digestive system. This is called an upper gastrointestinal endoscopy.

Alternatively, the doctor may choose to insert the tube through the anus to look at the lower part of the digestive system.

Learn about endoscopies here.


A colonoscopy is a type of endoscopy where doctors insert a long, narrow, flexible tube through the anus, into the rectum, and through into the colon. The colonoscope is usually long enough to look through the entire colon and sometimes the lower end of the small intestine.

Learn how to prepare for a colonoscopy here.


A biopsy is a procedure where doctors remove a small piece of tissue from the inside of a person’s intestine. Healthcare professionals will usually take a biopsy while they are carrying out another procedure, such as a colonoscopy or endoscopy.

Healthcare professionals may treat Crohn’s disease with a combination of medication, bowel rest, and surgery. Medicines cannot cure Crohn’s disease completely, but they can help reduce symptoms and make them more manageable.

Medications may include:

Many people find it helpful to incorporate lifestyle changes with this combination of treatment. For example, a person may identify certain foods that trigger their symptoms using a food diary. These foods can differ from person to person.

Surgery may also be an option for treating Crohn’s disease, with the NIDDK mentioning a study that showed nearly 60% of people required surgery within 20 years of having Crohn’s disease.

People can develop Crohn’s disease at any age, but people between 20–29 years old may be more likely to develop it, especially those who have a close family member with a Crohn’s diagnosis. A number of tests can help healthcare professionals diagnose Crohn’s disease, including blood or stool tests and colonoscopies.

Treatment for Crohn’s disease can help to keep symptoms at bay and allow people to live full and active lives free from discomfort, although there is currently not a cure for Crohn’s disease.