11.11 Inflammatory Bowel Disease
Inflammatory bowel disease (IBD) is a chronic disorder that is characterized by inflammation in the gastrointestinal tract. IBD is an umbrella term used to describe two disorders called ulcerative colitis and Crohn’s disease. In ulcerative colitis (UC), this inflammation is limited to the two layers of the colon, the mucosa and submucosa, most commonly in the rectum. In Crohn’s disease (CD), inflammation can occur anywhere in the GI tract, from the mouth to the anus, and the inflammation affects all three layers of the colon. With both disorders, signs and symptoms can also occur outside the GI tract, commonly referred to as extraintestinal manifestations. Neither ulcerative colitis or Crohn’s disease can be cured, and both disorders carry an increased risk for cancer of the GI tract.[1],[2],[3]
Both UC and CD are linked to an autoimmune response; however, the exact cause is unknown. It is thought that this autoimmune response could be triggered by normal intestinal bacteria, certain drugs/toxins, or infectious processes. There are also several risk factors for developing IBD[4],[5],[6]:
- Genetics/family history of IBD
- Clients aged 15-30 years and 60 or older
- Northern European/Jewish ancestry
IBD is also more common in developed countries and in cold climates.[7],[8],[9]
Pathophysiology
In IBD, extreme inflammation leads to breakdown of the mucosal layer of the GI tract. This breakdown allows exposure to intestinal viruses or bacteria that can also cause increased inflammation.[10],[11],[12]
In clients with UC, inflammation leads to edema and ulcerations that can bleed. This inflammation spreads in a uniform fashion, starting in the rectum and proceeding up the colon. Over time, the colon becomes inflexible and shortened, ultimately losing the folds (haustra) in the colon.[13],[14],[15]
In clients with CD, the inflammation starts out with a singular lesion, which goes on to develop into a deeper ulceration. Unlike UC, which has a uniform spread, a hallmark sign of CD are skip lesions. These are lesions that “skip” around the GI tract, leaving areas of normal or unaffected bowel between them. Over time, the affected areas develop a “cobblestone” appearance. The continued inflammation and resulting scar tissue can lead to the formation of strictures (narrowing) or fistulas (an abnormal passageway between two organs), causing bowel obstruction.[16],[17],[18] See Figure 11.33[19] for an illustration of the differences between CD and UC.
The inflammation of IBD is not limited to the GI tract and can occur in joints/bones, bile ducts, mouth (e.g., canker sores), eyes, and skin.[20],[21],[22]
Assessment
Physical Exam
Although UC and CD share similar characteristics, there are some key differences between the two in signs and symptoms that may be found during assessment. See Table 11.11 for the similarities and differences between the signs and symptoms of UC and CD.[23],[24],[25]
Table 11.11. Comparison of Ulcerativ