Dr Ian Berkowitz


Crohn’s & Ulcerative Colitis: Know the Difference?

You’ve had stomach cramps for weeks, you’re exhausted and losing weight, and you keep having to run to the bathroom. What’s going on?

It could be an inflammatory bowel disease (IBD). But which one?

There are two: Crohn’s disease and ulcerative colitis. They have a lot in common, including long-term inflammation in your digestive system. But they also have some key differences that affect treatment.

Crohn’s disease is a chronic inflammatory condition of the gastrointestinal tract and may affect any part from the mouth to the anus. 

Ulcerative colitis is a chronic inflammatory condition limited to the colon, otherwise known as the large intestine. By the way, if you hear some people just say “colitis,” that’s not the same thing. It means inflammation of the colon. With “ulcerative colitis,” you have sores (ulcers) in the lining of your colon, as well as inflammation there.

Shared Symptoms

The symptoms of Crohn’s disease or ulcerative colitis (UC) can be similar. They include:

Belly cramps and pain



An urgent need to have a bowel movement

Feeling like your bowel movement wasn’t complete

Rectal bleeding


Smaller appetite

Weight loss


Night sweats

Problems with your period. You might skip them, or their timing might be harder to predict.

You might not have all of those symptoms all the time. Both conditions can come and go, switching between flares (when symptoms are worse) and remission (when symptoms ease up or stop).

Crohn’s and ulcerative colitis are most often diagnosed in teenagers and young adults -- although they can happen at any age -- and tend to run in families.

What Sets Them Apart

There are three key differences:

1. Location.

Ulcerative colitis affects only the inner lining of the colon, also called the large intestine.

But in Crohn’s disease, inflammation can appear anywhere in the digestive tract, from the mouth to the anus. And it generally affects all the layers of the bowel walls, not just the inner lining.

2. Where the inflammation is.

People with Crohn’s disease often have healthy areas in between inflamed spots. But with UC, the affected area isn't interrupted.

3. Certain symptoms.

Most people who have Crohn's also have symptoms of ulcerative colitis. But rectal bleeding, or blood in the stools, is much more common in people who have UC than those with Crohn’s.

Because Crohn’s disease affects more of the body, it can cause some problems that doctors don't usually see in people who have ulcerative colitis. For instance:

Mouth sores between the gums and lower lip, or along the sides or bottom of the tongue.

Anal tears (fissures), ulcers, infections, or narrowing.

Getting the Right Diagnosis

Since the differences between the two conditions mostly revolve around where in the digestive system inflammation happens, the best way for a doctor to give you the right diagnosis is to take a look inside.

You might get tests such as:

X-rays that can show places where your intestine is blocked or unusually narrow.

Contrast X-rays, for which you'll swallow a thick, chalky, barium liquid so doctors can see how it moves through your system.

CT scans and MRIs to rule out other conditions that might cause symptoms similar to an inflammatory bowel disease.

Endoscopy, in which a doctor uses a tiny camera on a thin tube to see inside your digestive system. Specific types of endoscopy can:

Examine lower part of your large intestines. Your doctor will call this test "sigmoidoscopy."

Look at your entire large intestine. This is a colonoscopy.

Check the lining of the esophagus, stomach, and duodenum. This is an EGD (esophagogastroduodenoscopy).

Additional testing to look at your small intestine using a pill-sized camera. This is often called pill, or capsule, endoscopy.

See the bile ducts in the liver and the pancreatic duct. This test is called ERCP (endoscopic retrograde cholangiopancreatography).

Scientists are working to make two blood tests better at helping to diagnose ulcerative colitis and Crohn’s. They check on levels of certain antibodies found in the blood:

“pANCA” (perinuclear anti-neutrophil antibodies)

“ASCA” (anti-Saccharomyces Cerevisiae antibody)

Most often, people with ulcerative colitis have the pANCA antibody in their blood, and those with Crohn’s disease have ASCA in theirs. But for now, the tests have uncertain accuracy and should only be used in addition to the above testing.

Sometimes, even after all these tests, doctors might not be able to tell which of the two conditions you have. That's true for 1 in 10 people with IBD. They show signs of both diseases. So they get a diagnosis of “indeterminate colitis,” because it’s not clear which ailment it is.

Finding Your Treatment

Because of the similarities between the conditions, many treatments of ulcerative colitis and Crohn’s disease overlap. These things help for both:

Lifestyle changes. Those include diet tweaks, regular exercise, quitting smoking, and avoiding pain meds called “NSAIDs” (nonsteroidal anti-inflammatory drugs) such as ibuprofen. Stress management is also key. Stress doesn’t cause IBD, but it can lead to flare-ups. So try to cut down on the things that make you tense, and find ways to relax. Exercise is a great way to do that. So are other healthy things you might enjoy and find meaningful, such as hobbies, meditation, prayer, volunteering, and positive relationships.

Medicines can get inflammation under control:

"5-ASAs" work on the lining of your GI tract to lower inflammation. They work best in the colon. You might take them to treat an ulcerative colitis flare, or as a maintenance treatment to prevent relapses of the disease. Steroids curb the immune system to treat ulcerative colitis. Due to side effects, you probably wouldn't stay on them for a long time.

For severe disease, you may need drugs that work on the immune system. These include:

6-mercaptopurine (6-MP, Purinethol)

adalimumab (Humira)

adalimumab-atto (Amjevita), a biosimilar to Humira

azathioprine (Azasan, Imuran)

certolizumab pegol (Cimzia)


golimumab (Simponi)

infliximab (Remicade)

infliximab-dyyb (Inflectra), a biosimilar to Remicade

methotrexate (Rheumatrex, Trexall)

natalizumab (Tysabri)

ustekinumab (Stelara)

vedolizumab (Entyvio)

With the treatments for mild symptoms, almost all -- 90% -- of ulcerative colitis cases go into remission. If your UC is “refractory,” you’ll need continuous treatment with steroids.  With Crohn’s disease, complete remission is less common.  Some people eventually need surgery. That includes up to 45% people with ulcerative colitis and three quarters of people with Crohn’s. You and your doctor might talk about an operation if you have severe symptoms that aren’t helped by medications, if you get a blockage in your digestive tract, or if you get a tear or hole in the side of the intestine.

Keep Up With Your Checkups

If you have either condition, you'll need to keep up with your checkups, even if your symptoms start to ease up. You may also need to get colonoscopies more often and start them at a younger age. A colonoscopy can check for cancer or polyps that need to come out. Experts recommend that you start these tests within 8 to 10 years of developing UC or Crohn’s symptoms, and then every 1 to 3 years after that.

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