Home » IBD » What causes IBD?

What causes IBD?

Although much progress has been made in IBD research, investigators have not yet found a definitive answer to what causes these diseases. It has been established that the inflammation in IBD involves the interaction of a number of factors: the immune system, the genes a person has inherited, and certain elements in the environment (see Figure 3). Foreign substances (antigens) in the environment may somehow stimulate the body’s immune system to produce inflammation that continues without control. The theory is that once the IBD patient’s immune system is “turned on,” it does not know how to properly “turn off” at the right time. This results in inflammation that damages the intestine and causes the symptoms of IBD. This explains why the main goal of effective medical therapies has been focused on regulating the immune system better.

Much IBD research has led to progress in the fields of immunology, the study of the body’s immune defense system; microbiology, the study of microscopic organisms that reside in the bowel; and genetics, the study of the inherited DNA that control many of the body’s functions. Most scientists now believe that the reaction of the body’s immune system to an outside agent (such as a virus or bacteria) may be what triggers the disease, or that such an agent may cause damage to the intestinal wall, initiating or accelerating the inflammatory disease process. Through continuing research efforts, much more will be learned and a cure will eventually be found.

Figure 3: Etiology of IBD

What are the Causes of Inflammatory Bowel Disease (IBD)?
The exact causes of IBD remain unknown. Experts consider the following factors as being involved:

  • Heredity (having another family member with IBD)
  • An immune reaction to a “germ” ( a virus or bacteria) that damages the bowel
  • Abnormal regulation of the  immune system

IBD is probably not caused by an infection. It is not  contagious, and cannot be passed from person to person.

What are the Risk Factors for IBD?
A risk factor is something that increases one’s chance of getting a disease.
The following factors increase your chance of developing IBD:

  • Having a family member with IBD
  • Being Caucasian or of northern European ancestry
  • Being of Jewish ancestry (Ashkenazi)
  • Having problems with the immune system
  • Smoking increases the risk of Crohn’s disease