However, he failed to prove this connection because this organism could not be demonstrated microscopically or cultured. In 1932, Dr. Crohn and Dr. Ginzberg both come to the conclusion that this disease was not the basis of mycobacterial origin because their Crohn's patients were not found to have these bacteria visible microscopically by culture technique. Causes of Ulcerative Colitis and Crohn's disease are of unknown etiology, involving genetic and immunological influence on the gastrointestinal tract's ability to distinguish foreign from self-antigens. Crohn's disease tends to run in families. Studies have shown that about 20 to 25 percent of patients may have a close relative with either Crohn's or Ulcerative colitis.
Some people have remissions, periods when the symptoms go away, that last for months or even years.
However, most patients' symptoms eventually return. Normally, there is no obvious cause for a relapse. An event or substance can trigger a relapse but is not cause the disease. Some examples of these possible triggers include personal stress or worry, common infections such as colds or the flu, some drugs such as antibiotics, aspirin and anti-arthritics. Reduced appetite, poor absorption, and diarrhea rob the body of fluids, nutrients, vitamins, and minerals.