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.
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.
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:
Ulcerative colitis affects only the large intestine.
But in Crohn’s disease, inflammation can appear anywhere in the digestive tract, from the mouth to the anus.
2. Continuous inflammation.
People with Crohn’s disease often have healthy areas in between inflamed spots. But with ulcerative colitis, there are no healthy areas in between inflamed spots.
3. Which layers are affected.
Because Crohn’s disease affects more of the GI tract, it can cause some problems that doctors don't usually see in people who have ulcerative colitis. For instance:
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.
- 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 several blood tests better at helping to diagnose ulcerative colitis and Crohn’s. They check on levels of certain antibodies found in the blood. Two of these are:
- “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, Purixan)
- adalimumab (Humira)
- adalimumab-abdn (CyltezoTM)- a biosimilar to Humira
- adalimumab-atto (Amjevita) - a biosimilar to Humira
- azathioprine (Azasan, Imuran)
- certolizumab pegol (Cimzia)
- golimumab (Simponi, Simponi Aria)
- infliximab (Remicade)
- infliximab-abda (Renflexis) - a biosimilar to Remicade
- infliximab-dyyb (Inflectra) - a biosimilar to Remicade
- infliximab-axxq (Avsola) - a biosimilar to Remicade
- infliximab-qbtx (IXIFI) - a biosimilar to Remicade
- methotrexate (Rheumatrex, Trexall)
- natalizumab (Tysabri)
- tofacitinib (Xeljanz)
- 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 may 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 typically every 1 to 3 years after that. Your doctor will tell you a schedule that is best for you.