The chronic inflammatory bowl disease regional enteritis, or Crohn’s disease, is a condition that causes inflammation in the gastrointestinal tract. Although it can occur anywhere int he digestive tract, causing a correspondingly wide variety of symptoms, it most commonly is found in the ileum—the last section of the small intestine—and causes abdominal pain, bloody diarrhea, vomiting, and weight loss. While susceptibility to Crohn’s disease is inherited, the disease develops in response to environmental triggers and changes in the state of the microbes in the intestines that normally help with digestion. For example, antibiotic treatment can encourage the condition along, because it destroys beneficial gut bacteria, allowing other microflora to grow unchecked and upset the balance.
Crohn’s disease is generally believed to be an autoimmune disease, meaning the immune system treats a part of the body—in this case, the intestine—as an invader and responds accordingly. As with many autoimmune diseases, the industrialized world is involved in creating the environment in which the condition develops. The immune system is primed to attack parasites that are no longer prevalent, and locks on to the organs. Another view is that the immune system uses the parasites to practice on, and without having done so is poorly equipped to handle the gut microflora imbalance.
Risk factors for Crohn’s disease, in addition to a relatively clean upbringing and a family history of autoimmune disorders, include ethnic background (Ashkenazi Jews and French-Canadians are particularly prone to it) and cigarette smoking. Smoking not only increases the risk of Crohn’s, but it can worsen the disease when it does develop. Painkillers of the type called NSAIDs can also make it worse. Obesity is another factor, affecting "self-tolerance," or the immune system’s ability to recognize the organs as belonging there.
Treatment involves reducing inflammation, tamping down the immune system, and inhibiting the activity of a type of fat cell called TNF-α. A recent study determined that a class of drugs called thiopurines can be used to treat Crohn’s very successfully, reducing he need for surgery by more than 50 percent. Steroids are also used for the illness, though another study found evidence that steroidal treatment may increase the need for surgery, which may prompt a re-examination.