Key takeaways:
Crohn’s disease and ulcerative colitis are types of inflammatory bowel disease (IBD).
Irritable bowel syndrome (IBS) is a condition that does not involve inflammation of the bowel.
The symptoms of IBS and IBD can be similar, but the causes and treatment are different.
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 types of inflammatory bowel disease (IBD). IBS is a separate condition that doesn’t involve bowel inflammation.
IBS and IBD can have similar features, so it can be difficult to know what may be causing your symptoms. Your healthcare provider can help you understand the difference between IBS versus IBD and the best treatments for your symptoms.
IBD and IBS are very different, even though the symptoms can be similar. IBS is much more common than IBD. About 1 in 10 people have IBS. That makes IBS about 10 times more common than IBD.
Fortunately, IBS is also less serious. IBD is caused by inflammation and damage to the gastrointestinal (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 IBD and IBS are not clear. But experts have found some risk factors for each condition.
Risk factors for IBD include:
Family history
Genetics
Certain foods (high sugar)
Smoking (especially for Crohn’s disease)
Medications (like certain antibiotics, birth control pills)
Prior surgeries (like appendectomy)
Risk factors for IBS include:
Telling the difference between symptoms gets tricky. And IBS and IBD have many of the same symptoms.
Common symptoms of IBS include:
Loose and frequent stools
Constipation
Abdominal cramping or pain
In addition to the symptoms above, other symptoms are more likely to suggest IBD, including:
Weight loss
Diarrhea at night
Abnormal lab tests
To make a diagnosis of IBD, your provider will first ask all about your symptoms and do a physical exam. Then, you may have a combination of lab tests or imaging studies. This includes:
Blood work (like complete blood count)
Stool sample
Colonoscopy (with tissue samples)
CT scan or an MRI of your abdomen
On the other hand, there’s no specific test for IBS. Your provider will largely be able to make the diagnosis based on your symptoms. Your lab tests, imaging studies, and colonoscopy are usually normal in IBS and help to rule out other causes for your symptoms.
Treatment is very different for IBS and IBD. If you have IBD, you will take medications that lower the inflammation in the GI tract. These include medications like:
5-aminosalicylic acids (like mesalamine)
Steroids (like prednisone)
Immunomodulators (like azathioprine)
Biologic agents (like infliximab)
In severe cases, people may need surgery to remove any damaged parts of the bowel.
For IBS, your provider will focus on treating the specific symptoms you have. Changes to your diet and exercise habits are a good first step.
Here are a few examples of some foods to avoid when you have IBS:
Apples
Asparagus
Artificial sweeteners
Dairy
Soy products
Honey
Starches
If diarrhea is one of your main IBS symptoms, you might take medications that reduce the diarrhea, such as rifaximin (Xifaxan) and eluxadoline (Viberzi). If you’re more often constipated, you might take medications that help keep the GI tract moving, such as lubiprostone (Amitiza), linaclotide (Linzess), or plecanatide (Trulance).
Stress, anxiety, or depression can worsen IBS. If you and your provider think this is playing a role, treatment options include medications and therapy.
Ulcerative colitis and Crohn’s disease are both types of inflammatory bowel disease (IBD). IBD is an autoimmune disorder, meaning the immune system that usually fights off infections is mistakenly attacking your own body.
While they’re similar, there are some differences between ulcerative colitis and Crohn’s disease. These differences include:
Areas of the GI tract affected
Potential complications
Treatments
Let’s take a closer look at each condition to see the similarities and differences.
Crohn’s disease is a type of IBD where there is inflammation of the entire 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 which parts of the GI tract are involved. Common symptoms include abdominal pain, weight loss, and diarrhea.
If Crohn’s affects the lower part of the GI tract, such as the colon and the small intestine, you might also experience:
Abdominal pain
If Crohn’s affects the upper part of the GI tract, such as the stomach, you might experience:
Pain after eating
Nausea and vomiting
Bloating
There are also parts of the body that can show symptoms outside the GI tract. People with Crohn’s may experience:
Skin rashes
Eye pain and inflammation
Joint pain
Fatigue
Crohn’s disease can lead to some serious complications, such as:
Fistulas (a hole formed between the intestines and other body parts such as the skin, bladder, or vagina)
Abscesses (pockets of infection)
Strictures (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:
Diarrhea with blood or mucous
Abdominal pain or cramping
Sensation of incomplete emptying with bowel movements
Urgency to pass stool
Fatigue
Weight loss
And there can be symptoms outside of the GI tract, like:
Skin rashes
Eye pain and inflammation
Joint pain
Fatigue
Ulcerative colitis can also lead to some serious complications, such as:
Severe bleeding
Rupture of the colon
These complications may need surgery to treat them.
To figure out what’s causing your symptoms, work together closely with your healthcare provider and a GI specialist. This is especially important since the symptoms of Crohn’s disease and ulcerative colitis can be similar.
To get an accurate diagnosis, your GI specialist may do a colonoscopy, where they put a camera into the colon. They will look at the inside of the colon and take tissue samples.
Your providers might get a CT scan or an MRI of your abdomen to check for complications related to your condition.
Although both Crohn’s and ulcerative colitis are both forms of IBD, some medications work better for each condition. For example, if you have ulcerative colitis, aminosalicylates are commonly prescribed. But 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.
Keep in mind that many medication classes treat both conditions, so there’s a lot of overlap.
Gastrointestinal (GI) symptoms are a common feature of both inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). But there are important differences. IBD involves inflammation of the bowel and can lead to serious complications. IBS is much more common and a less serious condition.
Talk with your provider about your symptoms, even if they’re embarrassing. Getting the right diagnosis will make sure you get the right treatment.
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