An injection of carboxymethylcellulose (CMC) -- a common food additive -- may resolve ileal impaction horse colic. Ileal impactions are common in horses that eat Coastal Bermudagrass hay. Often, these cases are treated medically but surgery is sometimes indicated. Abdominal surgery is risky and recovery is slow.
Christopher G. Alford, DVM and R. Reid Hanson, DVM, Dipl. ACVS, ACVECC, veterinarians at Auburn University's College of Veterinary Medicine, found that "CMC penetrates and rehydrates the impaction, but its primary mechanism of action is lubricating the impaction, making it easier (for the ingesta) to pass into the cecum."
Read more about impaction horse colics here.