What is Inflammatory Bowel Disease?
Last updated: March 2020
The term inflammatory bowel disease (IBD) is used to describe several conditions including Crohn's disease and ulcerative colitis that involve chronic inflammation of the digestive tract. This chronic inflammation can cause serious damage to the gastrointestinal tract and often results in painful cramping and persistent diarrhea.
IBD can also have accompanying symptoms unrelated to the gastrointestinal system, such as arthritis or eye inflammation. IBD is not the same as irritable bowel syndrome (IBS) or celiac disease. Although these conditions share some symptoms with inflammatory bowel disease, IBS and celiac disease do not include the underlying inflammation or symptoms outside the digestive tract that are present in IBD.1,2
Over 1.6 million Americans are estimated to have IBD, and roughly 70,000 new cases are diagnosed in America each year. IBD can affect both children and adults but is most often diagnosed between 15-35 years of age.3
What are the different types of inflammatory bowel disease?
The term IBD encompasses several conditions, including Crohn's disease, ulcerative colitis, and indeterminate colitis. Although inflammation of the digestive tract is present in each condition, there are some key differences among them.
For example, Crohn’s disease can affect any part of the digestive tract. This includes the oral cavity, esophagus, liver, stomach, small intestine, large intestine, and rectum, all of which are critical structures in the digestion and nutrient absorption process.
Ulcerative colitis, on the other hand, affects only the rectum (anus) and the large intestine (colon). The inflammation pattern in Crohn’s disease is patchy in nature and encompasses the entire thickness of the intestinal or colon wall. In ulcerative colitis, the inflammation pattern is continuous and only affects the innermost layer of the intestinal wall.
On occasion, it may be hard to distinguish between these conditions, and an individual may be diagnosed with a condition called indeterminate colitis.1-3
What are the symptoms of Crohn's disease and ulcerative colitis?
Every individual’s experience with inflammatory bowel disease is different, however, there are some common symptoms that may occur. These include, but are not limited to:
- Abdominal pain and cramping
- Persistent diarrhea
- Blood in the stool
- Bleeding from the rectum
- Unexpected or unintended weight loss
- Reduced appetite
- Changes in bowel movement patterns, such as an urgent need to evacuate or a feeling of incomplete evacuation3,4
What are some of the complications of Crohn's and UC?
Beyond the direct symptoms of IBD, there are other complications that may accompany these conditions, including, but not limited to:
- Joint, eye, or skin inflammation (including arthritis, uveitis/iritis, erythema nodosum)
- Bowel obstruction or perforation
- Anal fissure (tearing of the skin around the anus)
- Fistulas (abnormal tissue connections between structures not normally connected)
- Severe dehydration
- Mouth sores
- Kidney stones
- Colon cancer
- Liver issues2,3
What causes inflammatory bowel disease?
The cause of IBD is currently unknown. Many experts agree that IBD stems from a complex interaction between genetics, the bacterial composition of the digestive tract, environmental factors, and the immune system.3
More specifically, it is often thought that the inflammation is due directly to the body’s immune system mistakenly attacking itself and the cells that line the gastrointestinal tract.1 There are several risk factors than can increase an individual’s risk of developing IBD, including age, medication usage, family history, cigarette smoking, race, ethnicity, and where an individual lives.2
How are Crohn's and ulcerative colitis diagnosed?
If your healthcare provider suspects you may have IBD after considering your symptoms and personal medical history, they usually recommend a scope be taken of your digestive tract. This scope involves inserting a long, thin tube with a camera and light attached into the body, either through the mouth (upper endoscopy) or through the rectum (colonoscopy), or sometimes both.
During the scope, a biopsy is performed, where a small sample of tissue is taken and analyzed. The results of the scope and biopsy will help diagnose an individual with IBD, as well as with the specific type of IBD that they have. If further testing is needed, your doctor may recommend other options such as an ultrasound, MRI (magnetic resonance imaging), or a CT (computed tomography) scan.5,6
What is the treatment for Crohn's, UC, and other types of IBD?
Treatment depends on the severity of the condition, previous treatment response, treatment side-effects, and other medical conditions the patient may have. Mild to moderate cases are often treated with anti-inflammatory medications or antibiotics that can be used on a long-term basis.
Antibiotics may also be specifically used as a short-term treatment for some of the complications from IBD, such as abscesses or wound infections. For moderate to severe cases, or when other medications have not been effective, biologic therapies may be used.
Immune system-suppressing medications are also used for moderate to severe cases, often in conjunction with another medication.
Corticosteroids are often prescribed as a short-term treatment for some symptoms of IBD, although they do not treat the underlying causes of those symptoms.
In some cases, surgery may be needed to remove diseased portions of the digestive tract, most often the small or large intestine. Often, the intestine can be reconnected after the diseased portion is removed, but sometimes may require the formation of an external stoma (i.e. ileostomy or colostomy) or an internal pouch (i.e. j-pouch).