In medicine, inflammatory bowel disease (IBD) is a group of inflammatory conditions of the large intestine and, in some cases, the small intestine.
The main forms of IBD are:
The main difference between the two is the location and nature of the inflammatory changes in the gut. Crohn's can affect any part of the gastrointestinal tract, from mouth to anus (skip lesions), although a majority of the cases start in the terminal ileum. Ulcerative colitis, in contrast, is restricted to the colon, and spares the anus.
Microscopically, ulcerative colitis is restricted to the mucosa (epithelial lining of the gut), while Crohn's disease affects the whole bowel wall.
Finally, Crohn's disease and UC present with extra-intestinal manifestations (such as liver problems, arthritis, skin manifestations and eye problems) in different proportions.
Although very different diseases, both present with diarrhea, hematochezia, weight loss and various associated complaints or diseases (arthritis, pyoderma gangrenosum , primary sclerosing cholangitis). Diagnosis is generally by colonoscopy with biopsy of pathological lesions.
All forms of IBD may require immunosuppression to control the symptoms. This consists of steroids, and later of steroid-sparing agents (such as azathioprine or methotrexate). Severe cases may require surgery, such as bowel resection , strictureplasty or a temporary or permanent colostomy or ileostomy.
While IBD can limit Quality of Life due to pain, vomiting, diarrhea, and other socially unacceptable symptoms, it is rarely fatal on its own. Fatalities due to complications such as toxic megacolon, bowel perforation and surgical complications are also rare.
While patients of IBD do have an increased risk of colorectal cancer this is usually caught much earlier than the general population in routine surveillance of the colon by colonoscopy, and therefore patients are much more likely to survive
A recent hypothesis posits that some IBD cases are caused by an overactive immune system attacking various tissues of the digestive tract because of the lack of traditional targets such as parasites and worms. The number of people being diagnosed with IBD has increased as the number of infections by parasites, such as roundworm and human whipworms , has fallen, and the condition is still rare in countries where parasitic infections are common. This is similar to the hygiene hypothesis applied to allergies.
Initial reports (Summers et al 2003) suggest that "helminthic therapy " may not only prevent but even cure (or control) IBD: a drink with roughly 2500 ova of the Trichuris suis helminth taken twice monthly decreased symptoms markedly in many patients. It is even speculated that an effective "immunization" procedure could be developed - by ingesting the coctail at an early age.
- Summers RW, Elliott DE, Qadir K, Urban JF Jr, Thompson R, Weinstock JV. Trichuris suis seems to be safe and possibly effective in the treatment of inflammatory bowel disease. Am J Gastroenterol 2003;98:2034-41. PMID 14499784.