Inflammatory bowel disease, also called IBD, is a name for a group of health conditions that cause swelling and irritation, called inflammation, of the gastrointestinal (GI) tract. This inflammation can make it hard for
the digestive system to break down and absorb nutrients from food. For more information about the digestive system and IBD, see “Anatomy and function of the GI tract” in
About Crohn’s and colitis.
Crohn’s disease, ulcerative colitis, and indeterminate colitis are all types of IBD. Indeterminate colitis is a term used when it is unclear if the disease is Crohn’s disease or ulcerative colitis. IBD is
not the same as
irritable bowel syndrome (IBS).
IBD is a lifelong disease. Although the inflammation can be treated with medicines, there is no cure. Learn more about the
symptoms of IBD and
treatment for IBD.
What is Crohn's disease?
Crohn’s disease is one of the 2 main types of IBD. Crohn’s disease gets its name from the doctor who first described the disease.
People with Crohn’s disease can have inflammation anywhere in their GI tract. The inflammation can be scattered throughout the GI tract, but is often located near the end of the small intestine (ileum) and the beginning of the large intestine. In some cases, the inflammation can spread to the tissue surrounding the GI tract and outside of the GI tract.
What is ulcerative colitis?
Ulcerative colitis is one of the 2 main types of IBD.
People with ulcerative colitis usually have inflammation in their colon, also called the large intestine. The inflammation can involve only parts of the colon or the entire colon. Typically, the inflammation is continual, meaning there are no breaks between areas of inflammation. It is rare for the inflammation to spread outside of the GI tract.
Differences between Crohn's disease and ulcerative colitis
Crohn’s disease and ulcerative colitis are not the same disease. Although there are many similarities between the two, there are also differences. The table below shows some of the differences between Crohn’s disease and ulcerative colitis.
|
|
Crohn's disease |
Ulcerative colitis |
|
Age at diagnosis |
Most commonly diagnosed between the ages of 15 to 35 years, but can be diagnosed at any age |
Most commonly diagnosed between the ages of 15 to 45 years, but can be diagnosed at any age |
|
Risk factors for diagnosis |
More common in females than males
Smoking increases risk
|
Similar risk for males and females
A history of smoking increases risk
|
|
Symptoms |
More likely to experience sores in the mouth and around the anus than with ulcerative colitis
Learn more about
IBD symptoms
|
More likely to experience blood in stool, rectal bleeding, and a sense of urgency than with Crohn’s disease
Learn more about
IBD symptoms
|
|
Location of inflammation in GI tract |
Scattered areas of inflammation
Most inflammation occurs between the end of the small intestine and start of large intestine
|
Continuous inflammation, but can have scattered inflammation once treated |
|
Depth of inflammation |
Deep (can extend into the organs surrounding the GI tract) |
Shallow |
|
GI tract complications |
- Fistulas (formation of tunnels between organs
- Blockage of GI tract
- Abscesses
- Sores
|
- Bleeding
- Rupture (perforation) of bowel
|
Adapted from
Crohn's and Colitis Canada
Causes
Scientists and doctors still don’t know the exact cause of IBD. There are usually many factors involved in developing IBD.
Risk factors are things that can increase your chance of developing IBD. These include your genetics, your environment, and your microbiome (microscopic bacteria, viruses, and other microbes that naturally live inside of you). Learn more about the risk factors and the things that can protect you from developing IBD at
Are you at risk?
IBD affects people of both sexes equally and can affect people of all races and ethnic groups. People of all ages can be diagnosed with IBD, but getting a diagnosis is most common in early adulthood.
If you are diagnosed with IBD, you may feel like one or some of your lifestyle choices are the reason you developed the disease. It is important to understand that
there is no single choice that a person makes that leads to developing IBD. In most cases, many factors are involved in developing IBD.
If you are having a hard time with your diagnosis or are dealing with feelings of sadness, anger, or guilt, learn more about
mental health and wellness and social support for people with IBD.
