Inflammatory Bowel Disease (IBD) - Insights
Inflammatory Bowel Disease (IBD) is a general term that usually refers to one of three different conditions:
Crohn's disease (CD)Ulcerative colitis (UC)Inflammatory bowel disease unclassified (IBDU)– often called Indeterminate colitis.
Indeterminate colitis is used to describe a child with IBD when physicians cannot determine with complete certainty whether the child has CD or UC.
A diagnosis of one or the other often becomes clear over time.
Differences Between Crohn’s Disease (CD) and Ulcerative colitis (UC)
CD may affect any part of the gastrointestinal tract from the mouth to the anus (the end of the bowel) but it can also be restricted only to the large intestine (colon). In comparison, UC only affects the large intestine (colon). However, CD and UC share enough features to group them both under the name inflammatory bowel disease (IBD).
Since some treatments only work on certain regions of the gastrointestinal tract, CD and UC may be treated differently. But sometimes, they both affect the same parts of the colon and in these instances, treatments will be similar. As well, both CD and UC cause inflammation (swelling and irritation) somewhere in the intestinal tract which may also have the same treatments.
The inflammation of UC is found only in the large intestine (colon) and in children this usually involves the whole colon (pancolitis). The term ulcerative is used because there are small shallow breaks - or ulcers - in the lining of the colon when UC is active.
CD simply means inflammation (-itis) of the large intestine (colon). There is also inflammation of the bowel with CD. But one of the main differences between CD and UC is that with CD inflammation may be anywhere along the gastrointestinal from the mouth to the anus (the end of the bowel). Another big difference between CD and UC is that the inflammation with CD may be deeper and sometimes, it can even make a hole though the bowel.
CD and UC both have a genetic component.
CD and UC Symptoms
The symptoms of CD and UC may be the same if the same part of the large bowel is involved. CD usually affects the last part of the small bowel and the first part of the large bowel. UC always affects the end of the large bowel.
Children with CD often have more problems with pain, fatigue, weight loss and growth without rectal bleeding as compared to children with UC.
IBD may also cause problems outside of the intestinal tract in other organs of the body.
What causes IBD?
Research suggests that IBD occurs when a person with inherited susceptibility to IBD is exposed to something in the environment. That may be something outside of the body, or something found within the bowels in close proximity to the lining of the intestinal tract. Immune cells are beneath this bowel lining. The inflammation of IBD occurs when the immune cells attack their own gastrointestinal (GI) tract.
Not all genes involved in CD and UC have been discovered. As well, not all specific environmental triggers have been found. It also isn’t clear why organs beyond the gastrointestinal tract become involved. Research that CHEO physicians are involved in, is trying to uncover some of these unidentified aspects of the disease. See CHEO IBD Current Research Studies
Indeterminate Colitis (IC) or Inflammatory Bowel Disease Unclassified (IBDU)
At times, after a gastroenterologist has thoroughly tested a patient, the physician cannot tell whether the IBD is CD or UC. This occurs when the person has IBD that involves the large intestine only (like UC) but has some features that suggest CD. These patients may be given a diagnosis of indeterminate colitis (IC) which is also called IBD unclassified (IBDU). Often patients with IC are treated very much like patients with UC, then re-evaluated later to see if their disease can then be called either CD or UC.
In summary IBD may be subdivided into three main groups: CD, UC and IC or IBDU. Once diagnosed, most people with IBD can be treated with medications and nutritional therapy to get the disease under control. Most children respond well to treatment and can lead a normal life. However, all children with IBD need long-term follow-up with a gastroenterology team for medical treatment, nutritional assessments and emotion support.