Cobblestone ulcers are small, closely packed lesions that look a lot like a cobblestone street or sidewalk. People with Crohn’s disease may have them in their gastrointestinal (GI) tract.

Crohn’s disease is a chronic inflammatory condition. It can affect any part of the gastrointestinal (GI) tract, from the mouth to the anus.

When diagnosing Crohn’s disease, doctors may recommend a type of endoscopy known as a colonoscopy to examine the GI tract more closely. With this procedure, they can look for signs of Crohn’s disease, including cobblestone ulcers.

The following article describes what cobblestoning is, how doctors discover it, and more information on the signs and symptoms of Crohn’s disease.

Crohn's disease can cause a cobblestone-like appearance on the gastrointestinal tract.Share on Pinterest
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Crohn’s disease causes inflammation and ulcers in the GI tract. Research has shown that Crohn’s-related ulcers often appear in three different patterns, including:

  • Aphthous ulcers: These shallow, small ulcers look similar to canker sores that can appear in the mouth.
  • Longitudinal ulcers: These larger ulcers often have breaks or gaps.
  • Cobblestone appearance: These are clusters of ulcers that connect and resemble a cobblestone street.

Doctors may use these features to distinguish Crohn’s disease from ulcerative colitis, another inflammatory bowel disease. Johns Hopkins Medicine notes that a cobblestone appearance of ulcers is a distinguishing feature of Crohn’s disease.

Endoscopes are long, thin, flexible tubes that healthcare professionals can insert into various parts of the body. A doctor can use them to diagnose certain conditions, collect a tissue sample, or perform other minor procedures.

To check for Crohn’s disease, a person will need a specific type of endoscopy known as a colonoscopy. This is when doctors insert a tube into a person’s body to examine their colon.

Preparing for the procedure

A person should follow instructions from a healthcare professional to prepare for the outpatient procedure. Some general steps a person can take to prepare for the procedure include:

  • speaking with their doctor about when and if to stop taking certain medications and supplements, such as blood thinners or iron
  • following a low-fiber diet for a few days prior to the colonoscopy
  • following a clear liquid diet, beginning the day or 2 days before the procedure
  • speaking with their doctor about medication to clear the bowel

A person should also speak with their doctor about arrival times and any special instructions for the day before and day of the procedure.

During the procedure

A colonoscopy may take between 30–60 minutes, though this can vary. A person should expect to be in the hospital or doctor’s office for a longer time than this to allow for preparation and recovery.

Though different doctor’s offices will vary slightly, a person may expect some of the following during the colonoscopy:

What to expect during a colonoscopy

  • A person will change into a hospital gown.
  • They may review their health history with an anesthesiologist.
  • During the procedure, the person will lie on their side with their knees bent.
  • A nurse or tech will insert an IV line to supply medicines during the procedure.
  • The person may receive a sedative.
  • A doctor will insert the endoscope into the rectum and examine the colon.
  • After the procedure, the person will wake in a recovery room and be able to go home once they have recovered.
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Learn more about what to expect during a colonoscopy here.

Crohn’s disease can affect any part of the GI tract, from the mouth to the anus. This means that a person may experience symptoms in a variety of areas.

According to the Crohn’s & Colitis Foundation, some common symptoms related to inflammation in the GI tract include:

Extraintestinal symptoms

Crohn’s disease can affect other areas of the body as well as the GI tract. Some additional symptoms that could indicate a person has this condition include:

Learn more about the pathology of Crohn’s disease, including extraintestinal symptoms, here.


Finally, Crohn’s disease can lead to more severe complications if a person does not receive adequate or timely treatment. Some complications that may result from Crohn’s disease include:

  • improper growth in children
  • low energy
  • fissures or tears in the anus
  • strictures, which involve the narrowing of the intestines due to frequent inflammation
  • formation of fistulas or channels between parts of the intestine or between the intestine and other organs

Learn about some more serious complications of Crohn’s disease here.

Additional tests a person may undergo before receiving a diagnosis of Crohn’s disease include:

  • Blood tests: Blood tests can reveal signs of anemia, inflammation, or infection to doctors.
  • Stool tests: Doctors may notice markers of inflammation and certain bacteria in a stool sample that could help them identify Crohn’s disease.
  • MRI scan: This type of imaging uses magnetic rays rather than radiation. It allows doctors to see the entire length of the small bowel.
  • CT scan: Doctors may use a CT scan to see a cross-sectional image of a person’s GI tract.
  • Small intestine imaging: During this test, a person swallows a small camera. It is about the size of a pill. The camera takes snapshots of the person’s GI tract before the person expels the camera in their stool.
  • Biopsy: Doctors may take a sample of a person’s intestine. They can do this during a colonoscopy or endoscopy.

Learn more about tests and procedures to diagnose Crohn’s disease here.

Crohn’s disease inflammation often leads to the formation of ulcers. At times, these ulcers can appear close together in the intestines and resemble the appearance of cobblestones.

Doctors can use the appearance of cobblestoning as part of their diagnostic process. They may find this marker during a colonoscopy. However, they will also look for several other symptoms and markers using different types of tests.