You can check out the information provided by St. Luke's Health Watch for an overview of the common forms. Also, the Scripps Clinic provides a list of links to several IBD sites. Inflammatory cells are those cells responsible for fighting infection or reacting to various types of body tissue injury. In IBD, these inflammatory cells, of one type or another, invade the wall of the stomach or intestine. These cells, because they don't normally belong in the lining of the stomach or intestine, result in changes that cause irritation and abnormal functioning of the bowel.
Some animals also show loss of appetite.
The causes of inflammatory bowel disease are poorly understood and largely unknown. Although I'll talk more about treatment in part 3 of this article, some veterinarians believe that a subset of IBD cases are secondary to bacterial infection. This belief stems out of the observation that certain cases are responsive to antibiotic therapy. A specific spiral bacteria called Helicobacter can cause inflammation of the stomach and ulcers in humans. There is evidence that the majority of cases of IBD result from activation of the immune system .