Equine enteritis (duodenitis-proximal jejunitis), an inflammation of the small intestine, usually affects the part of the small intestine closest to the horse's stomach.
The inflammation reduces the intestine's motility, reducing its ability to absorb fluids. Large amounts of fluid accumulate in the intestine and the horse can become dehydrated.
Symptoms of enteritis include abdominal pain and diarrhea as well as kicking and rolling common to colic. Enteritis should be treated by a veterinarian.