A 5-month-old Thoroughbred colt presented to Cornell's Equine Emergency Service for a two-day history of abdominal pain and recent-onset diarrhea. On presentation the foal was tachycardic, tachypneic, and mildly hyperthermic. His mucous membranes were hyperemic with a prolonged capillary refill time. An abdominal ultrasound showed diffusely hypomotile and fluid filled small and large intestinal structures as well as a distended stomach and mildly increased peritoneal fluid. The foal was placed on supportive therapies including fluid therapy, a non-steroidal antiinflammatory, antibiotics, and gastroprotectants pending the results from diagnostic tests. Since this foal was 5-months old and had been healthy to date, his abdominal pain was most likely to be caused by enterocolitis due to a recently acquired infectious agent or a mechanical obstruction such as ascarid impaction or intussusception. The most common infectious causes of enterocolitis in foals include Rotavirus, Clostridium difficile, Clostridium perfringens, Lawsonia, Salmonella, and intestinal parasites (specifically cyathostomes). Less commonly, Coronavirus and Potomac Horse Fever have also been reported to cause colitis in foals. Fecal and blood samples were submitted to test for the above infectious agents and all tests came back negative with the exception of the fecal floatation, which was positive for both strongyles and Parascaris equorum. The foal’s clinical signs waxed and waned during the first two weeks of hospitalization. Intermittently he would develop a fever, toxic line on mucous membranes, azotemia, and bounding digital pulses. These episodes were attributed to endotoxic events associated with translocation of bacteria across his compromised gut wall. Although a definitive diagnosis was not made, the colt responded to supportive care and treatment of presumed endotoxemia-induced laminitis, an unusual sequelae in foals. This report will discuss enterocolitis in foals including differential diagnoses, treatment, and subsequent complications of the disease.