There is no underlying cause of IBD in 75% of cases. They are thought to reflect an exaggerated or inappropriate response by the immune system to dietary, bacterial or self-antigens. IBD is a diagnosis of exclusion. Other differential diagnoses have to be investigated and ruled out before a diagnosis of IBD can be made. | There is no underlying cause of IBD in 75% of cases. They are thought to reflect an exaggerated or inappropriate response by the immune system to dietary, bacterial or self-antigens. IBD is a diagnosis of exclusion. Other differential diagnoses have to be investigated and ruled out before a diagnosis of IBD can be made. |