Key takeaways
- Both Crohn’s disease and ulcerative colitis (UC) involve inflammation of the digestive tract caused by an abnormal immune response. But the two conditions affect different areas of the intestines.
- Treatment for either condition may involve medications and, in some cases, surgery. Crohn’s disease is more likely to require surgery than UC.
- While UC affects only the colon, Crohn’s can cause complications throughout the digestive tract and in other parts of the body, including the skin, eyes, joints, and liver.
People can get confused when it comes to differentiating between inflammatory bowel disease (IBD), Crohn’s disease, and ulcerative colitis (UC).
The short explanation is that “IBD” is an umbrella term for the other two conditions. So, Crohn’s disease and UC are two types of IBD. But there’s much more to the story.
Both Crohn’s and UC involve an abnormal immune system response, and they may share some symptoms. But there are important differences between the two conditions, especially regarding the location of inflammation in the gastrointestinal (GI) tract and the way each responds to treatment.
This article takes a closer look at the key differences between Crohn’s and UC, including symptoms, possible complications, and treatment approaches.
IBD occurs mainly in developed countries such as the United States. As with other autoimmune and allergic conditions, experts believe that a loss of certain gut bacteria partially contributes to diseases such as IBD. Genetic factors may also play a strong role in IBD development.
When you have IBD, your immune system mistakenly attacks your GI tract, causing chronic inflammation.
Crohn’s and UC are both forms of IBD.
For most people, IBD is a lifelong disease with alternating periods of remission (when symptoms decrease or even stop) and flare-ups (when symptoms return or become more intense).
There’s currently no cure for IBD, but modern treatments allow many people to live relatively typical, active lives. Treatment focuses on managing symptoms, with remission as a goal.
Inflammatory bowel disease (IBD) vs. irritable bowel syndrome (IBS)
IBD should not be confused with irritable bowel syndrome (IBS). While some of the symptoms may be similar at times, the two conditions differ significantly in source and course.
You can read more about the differences between these two conditions here.
Crohn’s disease may cause inflammation in any part of the GI tract, from the mouth to the anus, but it most often affects the end of the small intestine (also called the small bowel) and the beginning of the colon (also called the large intestine or large bowel).
Symptoms
Symptoms of Crohn’s disease can include:
- frequent diarrhea
- occasional constipation
- abdominal pain
- fever
- blood in the stool
- fatigue
- skin conditions
- joint pain
- malnutrition
- weight loss
- fistulas
Crohn’s isn’t limited to the GI tract — it may also affect the skin, eyes, joints, and liver. Since symptoms usually get worse after a meal, people with Crohn’s will often experience weight loss due to food avoidance.
Complications
Crohn’s disease can cause blockages in the intestine as a result of scarring and swelling. Ulcers (sores) in the intestinal tract may develop into tracts of their own, known as fistulas.
Crohn’s disease can also increase the risk of colon cancer if the disease affects one-third of the colon or more. If Crohn’s affects less than one-third of the colon or does not affect the colon at all (instead affecting only the small intestine), then there’s no increased risk of colon cancer.
Treatment
Medication is the most common treatment for Crohn’s disease. The four types of drugs a doctor may recommend are:
- steroids (temporarily)
- antibiotics (if infections or fistulas cause abscesses)
- immunomodulators, such as azathioprine and 6-MP
- biologic medications
In some cases, surgery may also be necessary, although surgery will not cure the disease.
Unlike Crohn’s, UC is confined to the colon (large intestine) and affects only the mucosa and submucosa (the top layers of the intestine) in an even distribution.
Symptoms
Symptoms of UC include:
- abdominal pain
- loose stools
- bloody stool
- bowel movement urgency
- fatigue
- loss of appetite
- weight loss
- malnutrition
The symptoms can vary depending on the type of UC you have. According to the Crohn’s & Colitis Foundation, there are three types of UC that affect different parts of the colon:
- Left-sided colitis: This type affects the rectum, the sigmoid colon, and sometimes the descending colon.
- Ulcerative proctitis: This is the mildest form of UC and affects only the rectum.
- Extensive colitis: This type of UC affects the entire colon.
Complications
When complications occur, they can be severe. If left untreated, UC may lead to:
- perforation (holes in the colon)
- colon cancer
- liver disease
- osteoporosis
- anemia (low red blood cell count)
Treatment
Surgery is much less common in UC than in Crohn’s — 10% to 30% of people with UC will need surgery at some point, while 50% to 80% of people with Crohn’s will.
Surgical procedures used to treat UC and Crohn’s involve removing part of the intestine or, in some cases, the entire colon.
Because the colon is very important, surgery is considered a last resort. Doctors typically consider surgery only when it’s difficult to bring IBD into remission and when other treatments, such as medications, have been unsuccessful.
IBD can significantly decrease your quality of life by causing uncomfortable symptoms and frequent bathroom visits. It can even lead to scar tissue and increase the risk of colon cancer.
If you experience any unusual symptoms, it’s important to contact your doctor. They may refer you to a gastroenterologist for IBD testing, such as a colonoscopy, a sigmoidoscopy, or a CT scan. Your doctor may also order blood and fecal testing.
These tests will help doctors find out which specific form of IBD you have so that they can more effectively treat it.
Commitment to daily treatment and lifestyle changes can help minimize IBD symptoms, bring the disease into remission, and reduce the chances of complications.
Support groups can help you connect with other people who are living with this condition. You can visit the following sites to learn more:
You can also visit Healthline’s IBD resource center to learn more about IBD, and consider joining Bezzy IBD to connect with people who understand.
Bezzy IBD is a community where you can meet others who are living with Crohn’s and UC through one-on-one messaging and live group discussions. Plus, you’ll have expert-approved information on managing IBD at your fingertips.