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Crohn's Disease: Symptoms, Diagnosis & Treatment

Biodigital human digestive system
The digestive system includes the esophagus, stomach, liver, pancreas, gallbladder, small intestine and large intestine. (Image credit: The BioDigital HumanTM developed by NYU School of Medicine and BioDigital Systems LLC)

Crohn’s disease is a chronic inflammatory bowel disease (IBD) that involves inflammation in all or part of the digestive tract. Parts of the digestive system become swollen and develop deep sores or ulcers. Though Crohn’s can develop anywhere in the digestive tract from the mouth to the anus, it most often affects the last part of the small intestine and the first part of the large intestine, according to the Crohn's & Colitis Foundation of America.

"We don’t what the cause is," said Dr. Razvan Arsenescu, a gastroenterologist at The Ohio State University's Wexner Medical Center in Columbus. Several genetic abnormalities are linked to the disease, but these only explain about 20 percent of cases, Arsenescu told Live Science.

Studies show that harmless bacteria in the intestine, which the immune system normally ignores, trigger an immune response in people with Crohn's, said Dr. Sophie Balzora, a gastroenterologist at NYU Langone Medical Center in New York City. "Why that response occurs, nobody truly knows," Balzora told Live Science.

Those with Ashkenazi Jewish ancestry may have a higher chance of developing Crohn’s disease. It's less common among African Americans and Hispanics, although the number of cases in these populations is rising, Balzora said. Smoking is another risk factor for Crohn's. The disease affects men and women equally, runs in families, and most commonly starts in people between the ages of 15 and 35, according to the Crohn's & Colitis Foundation of America.


The symptoms of Crohn’s disease tend to focus on the digestive area. Abdominal pain and diarrhea, often with blood and sometimes up to 20 times a day, are common in Crohn’s patients. Because the body is struggling to properly digest food, and abdominal pain can lessen the appetite, weight loss is another common sign of Crohn’s disease. Other symptoms include mouth sores, bowel blockages and anal tears/fissures. These symptoms can lead to complications like anemia, osteoporosis, arthritis, and skin problems. 

In Crohn’s disease, the intestinal wall is thickened and inflamed by swelling and scar tissue, narrowing the passageway for food that is being digested. When the intestine has narrowed, this is referred to as a stricture. One serious complication of Crohn’s disease is a fistula — ulcers that develop so deep that they create openings and tunnels to other organs. For example, an ulcer might develop and connect the intestines to the bladder, to the small bowel, or to the skin, all of which can cause serious infections.

Symptoms may flare up thanks to infections, hormonal changes during a woman's menstrual cycle, smoking, failing to take medication, or anytime the body is under stress, Balzora said. Some patients go for a long time without symptoms (known as remission) then suffer the occasional flare up, while other patients have ongoing severe symptoms. Crohn’s disease can also worsen and progress, so it’s important to be aware of this. Call your doctor immediately if you feel faint or your pulse is abnormal, you have severe abdominal pain, fever or shaking chills, or persistent vomiting.

"Crohn's disease can differ for every single person," Balzora said.

Diagnosis & treatment

There are a number of ways to diagnose Crohn’s disease. Your doctor will first analyze your symptoms and do a physical exam before ordering tests. Tests that diagnose Crohn’s disease include:

  • Blood work
  • Barium X-rays/CT scans/MRI scans of the colon or small intestine
  • Colonoscopy/sigmoidoscopy/video capsule endoscopy and biopsy
  • Stool analysis

Crohn’s disease isn’t curable, but the symptoms can be managed and treated to make sure that the patient has as normal a life as possible. Because patients have a wide range of symptoms, from mild to severe, there are varying ways of dealing with Crohn’s disease. Exercising, a healthy diet, and avoiding smoking can help alleviate many of the symptoms. However, "diet and exercise are not going to change the course of the disease," Balzora cautioned.

The most common treatment for Crohn’s disease is prescription medication. Patients can use over-the-counter medicines to treat diarrhea and other mild symptoms, but prescription medications will be needed to control inflammation in the intestines and prevent complications of the disease from occurring. Medications can help heal damaged tissue and postpone the need for surgery.

Some of these drugs include:

  • Biologics, such as infliximab (trade name Remicade), natalizumab (Tysabri), or Vedolizumab (Entyvio), which are delivered intravenously; or itolizumab (Alzumab), certolizumab pegol (Cimzia), or golimumab (Simponi), which can be taken at home. Vedolizumab (Entyvio) was approved by the U.S. Food and Drug Administration in June 2014.
  • Antibiotics to reduce bacterial growth caused by strictures or fistula
  • Corticosteroids, such as azathioprine (trade name Azasan), 6-mercaptopurine (Purinethol), methotrexate (Trexall)

Up to 80 percent of Crohn’s disease patients will need surgery at some point to correct problems like strictures, fistulas or intestinal bleeding. Though surgery can relieve some of the symptoms, it cannot cure Crohn’s disease, as the disease occurs in patches across the entire digestive system. While parts of the system can be removed, the Crohn’s disease could simply appear in a different part of the system.

Types of surgery include:

  • Strictureplasty — the strictured/narrowed area is widened without any intestinal removal
  • Bowel resection — the damaged part of the small intestine is removed and the healthy ends surgically attached
  • Large intestine removal — as the name implies, the large intestine is removed and an external pouch is attached for the collection of waste draining out of the body. The patient must empty the pouch several times a day for the rest of their lives
  • Abscess drainage — Collections of pus or infection inside the abdominal cavity or around the anus are drained.

Coping with Crohn’s disease can be stressful, as it affects every part of a patient’s life. It’s important to have a good support system in family and friends. There are also support networks out there for people suffering from Crohn’s disease and other inflammatory bowel diseases, and their loved ones. Some Crohn’s disease sufferers seek counseling and therapy to help cope. Alternative treatments could also help your well-being. Though they aren’t proven to treat Crohn’s disease, they could alleviate symptoms and lower stress. These treatments include herbal supplements, acupuncture, and massage.

Because Crohn’s disease makes it hard for your body to absorb nutrients from food, patients need to focus on a healthy meal plan that is high-calorie and high-protein to ensure that you’re getting the right nutrients. Try eating regular meals plus two or three snacks a day.


There is no way to prevent Crohn's disease, but factors in early childhood could play a role. For example, the diet that mother has during pregnancy may be important (e.g., not eating red meat), and vaginal delivery of babies may be better than cesarean section because of the bacteria acquired during birth, said Dr. Arsenescu, of Ohio State University. Breastfeeding, avoiding antibiotics and providing a smoke-free environment may also reduce the risk of a child developing Crohn's, he said.

Additional reporting by Elaine J. Hom, Live Science Contributor

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Tanya Lewis
Tanya Lewis
Tanya was a staff writer for Live Science from 2013 to 2015, covering a wide array of topics, ranging from neuroscience to robotics to strange/cute animals. She received a graduate certificate in science communication from the University of California, Santa Cruz, and a bachelor of science in biomedical engineering from Brown University. She has previously written for Science News, Wired, The Santa Cruz Sentinel, the radio show Big Picture Science and other places. Tanya has lived on a tropical island, witnessed volcanic eruptions and flown in zero gravity (without losing her lunch!). To find out what her latest project is, you can visit her website.