Here's what you should do:
* Call your veterinarian immediately. They can assess the situation and determine the best course of action.
* Observe your horse closely. Note any changes in behavior, such as restlessness, pawing, sweating, or rolling.
* Keep your horse calm and comfortable. Avoid moving him if possible, and provide a quiet, safe environment.
* Be prepared to provide your veterinarian with as much information as possible, such as the horse's age, breed, recent diet, and any previous health issues.
It's important to remember that colic can be life-threatening, and prompt veterinary attention is crucial for the horse's well-being.