My spouse worked in a vet emergency clinic. A lot of animals came in for intestinal blockages. It rarely ended well. Best case scenario, the owner realized early enough that something was going wrong, and they had enough money to pay for an expensive abdominal surgery to remove the blockage. The more usual scenario was that it was too late by far, and the pet had to be euthanized.

They had one horrific story of a dog swallowing fishhooks; the owner took the dog home AMA after the vet was unable to get the hooks out without surgery. It almost certainly ended up dying a horrific, agonizing death.