Another common use for stomach pumping is to help clear the digestive tract before stomach surgery or an endoscopy. Before most surgeries and endoscopies, you'll be told not to eat or drink anything several hours before the procedure, which helps make sure everything is cleaned out and the doctors can see what they're doing. It also makes the anesthesia more effective. In some cases, however, it's necessary to take the extra step of washing the stomach, especially if the procedure is an emergency, the patient is unconscious or there is bleeding in the stomach that could obscure the camera's view [source: Kleinman].
Another reason to clean out the stomach is after surgery or trauma. In those situations, stomach pumping can be used to clear out any blood or fluids that may have collected in the stomach.