Ulcerative colitis, Crohn’s disease, and irritable bowel syndrome (IBS) are three conditions that are often confused with one another. Crohn’s disease and ulcerative colitis are both types of inflammatory bowel disease (IBD). Meanwhile, IBS is a separate condition — not to be confused with IBD. These conditions may share some similarities, but they are very different. Although the symptoms may seem similar, working with your healthcare provider to figure out which one you have is important because each requires different treatments.
Ulcerative colitis and Crohn’s disease are both types of IBDs (inflammatory bowel diseases). IBDs are autoimmune disorders, meaning the immune system that usually fights off infections is mistakenly attacking your own body.
Crohn’s disease is a type of IBD where there is inflammation of the entire gastrointestinal (GI) tract, or parts of it, from mouth to anus. In addition, the entire thickness of the bowel wall is involved in Crohn’s disease, which can lead to some serious complications.
The symptoms of Crohn’s disease depend on what parts of the GI tract are involved. Common symptoms include abdominal pain, weight loss, and diarrhea.
If the lower part of the GI tract — such as the colon and the small intestines — are involved, you might also experience:
If the upper part of the GI tract — such as the stomach — is involved, you might experience:
Pain after eating
Nausea and vomiting
There are also parts of the body that can show symptoms outside the GI tract. People with Crohn’s may experience:
Eye pain and inflammation
Crohn’s disease can lead to some serious complications, such as:
Fistulas, where a hole is formed between the intestines and other parts of the body such as the skin, bladder, or vagina
Abscesses, which are pockets of infection that may need surgery or a procedure to drain them
Strictures, which are a narrowing of the bowel that can lead to blockages
Cancers of the GI tract
Ulcerative colitis is another type of IBD. It’s also an autoimmune disorder. Unlike Crohn’s disease, ulcerative colitis only involves the colon, or large intestines. It only affects the inner lining of the colon, instead of the whole wall thickness.
Symptoms of ulcerative colitis include:
Bloody or mucousy diarrhea
Abdominal pain or cramping
Sensation of incomplete emptying with bowel movements
Urgency to pass stool
There are some symptoms outside of the GI tract that you may also experience:
Eye pain and inflammation
Ulcerative colitis can also lead to some serious complications, such as:
Rupture of the colon
These complications may need surgery to treat them.
It’s important that you, your healthcare provider, and a GI specialist work together closely to figure out what’s causing your symptoms. This is especially important since the symptoms of Crohn’s disease and ulcerative colitis can be similar. Your providers may check blood work and a stool sample. To get an accurate diagnosis, your GI specialist may do a colonoscopy, where a camera is pushed into the colon. Your provider will look at the inside of the colon and take tissue samples, which are important for making the right diagnosis. Your providers might get a CT scan or an MRI of your abdomen to check for complications related to your condition.
Although the medications may seem similar, there are differences in how Crohn’s disease and ulcerative colitis are treated. Many medication classes treat both conditions, so there is a lot of overlap. However, there are enough differences that getting the right diagnosis is important. For example, people with ulcerative colitis usually take aminosalicylates, while only a limited number of people with Crohn’s disease will benefit from these medications. When it comes to more advanced therapies like biologic agents, some can only be used for ulcerative colitis and some can only be used for Crohn’s disease.
Getting the correct diagnosis can be tricky. Sometimes it might look like you have ulcerative colitis at first, but later your providers will find out that it’s actually Crohn’s disease. Work closely with them to be sure you get the right treatment.
Yes! IBD and IBS are very different, even though the symptoms can be similar. Most importantly, the treatments are not the same. Working with your provider to figure out what condition you have is important so that you can find the best treatment.
Fortunately, it’s also less serious. IBD is caused by inflammation and damage to the GI tract. With IBS, this isn’t the case. IBS is a collection of gut symptoms caused by unusual functioning of the bowel.
The exact causes of both IBD and IBS are not clear. With IBD, your genes play a strong role, and it runs in families. There are also many other things that can contribute, such as certain foods, smoking (especially for Crohn’s disease), and missing medication doses. With IBS, many factors are thought to be involved, but stress and diet play a big role. Sometimes people develop IBS after infections as well.
Where it gets complicated is that many of the symptoms of IBS are also seen in IBD.
Common symptoms of IBS include:
Loose and frequent stools
Abdominal cramping or pain
Some symptoms are more concerning for IBD. Make sure you talk with your provider about:
Severe or worsening symptoms
Diarrhea at night
Any blood work that isn’t normal, such as low iron
To make a diagnosis, your provider will want to know about your symptoms. Depending on what those symptoms are, your provider will have a better sense of what tests to do next. For example, you may need to keep a food diary, have blood work, or provide a stool sample. If your symptoms are concerning for IBD, you might need a colonoscopy. This is a test where a specialist pushes a camera into the colon so they can look for signs of IBD and take tissue samples. You might also need to get a CT scan or an MRI of your abdomen. You and your providers will consider all of this information to figure out your diagnosis.
Treatment is very different for IBS and IBD. If you have IBD, you will take medications that lower the inflammation in the GI tract — such as anti-inflammatory medications, biologic agents, and immunomodulators — which can reduce the damage IBD is causing.
Here’s a few examples of some foods to avoid when you have IBS:
If diarrhea is one of your main IBS symptoms, you might take medications that reduce the diarrhea, such as rifamixin (Xifaxan) and eluxadoline (Viberzi). If you are more often constipated, you might take medications that help keep the GI tract moving, such as lubiprostone (Amitiza), linaclotide (Linzess), or plecanatide (Trulance).
Talk with your provider about your symptoms, even if they are embarrassing. Getting the right diagnosis is important to make sure you are getting the right treatment.