Cats can suffer from several large bowel diseases. Here are descriptions of the three most common types:

Idiopathic Juvenile Diarrhea: Kittens diagnosed with idiopathic juvenile diarrhea suffer from a chronic, voluminous diarrhea suggestive of low-grade large-bowel inflammation. The kittens are bright, alert and eat well. It is after the veterinarian has exhausted his or her diagnostic menu that the doctor must throw up his or her hands and declare the diarrhea idiopathic--a condition that develops without apparent or known cause.

Inflammatory Bowel Disease: IBD refers to a diverse group of chronic syndromes in which the mucosa of the small and/or large intestine is infiltrated by inflammatory cells usually associated with the immune system. When no cause-bacteria, parasites or food allergy-can be found, the disease is named idiopathic inflammatory bowel disease.

Megacolon: Megacolon refers to a condition in which the diameter of the colon is increased, resulting in reduced motility of the large intestinal tract and in constipation. Constipation does not cause megacolon, but cats suffering from megacolon are constipated. This condition occurs because fecal matter is retained in the expanded tract. Idiopathic megacolon is more prevalent in middle-aged to older cats.