One of the worst-case scenarios, and also the most common, in which stomach pumping is used is to save you from an overdose or poisoning. After someone overdoses on drugs, alcohol or medication, or ingests a poison, pumping the stomach can help stop whatever remains from getting absorbed into the body. It can also reduce the impact of the drug or poison and possibly even save the person's life.
Whether the overdose is accidental or intentional, stomach pumping is one of the most common procedures for helping a patient recover from ingesting unwanted substances. The sooner you're taken to the hospital after an overdose or poisoning, the more the doctors will be able to remove from your stomach before it enters the bloodstream.
Most drug overdoses involve over-the-counter medications, however when the substance in the stomach is a corrosive -- such as lye or ammonia -- gastric lavage is not performed because the substance could also corrode the tube and equipment used to perform the pumping [sources: Jacoby; Lippincott's Nursing Procedures]. If that happens, fluid could leak -- possibly into the lungs -- causing further harm to the patient [source: Jacoby].
After pumping, a solution containing activated charcoal is often introduced into the stomach. It's thought to help prevent any remaining poisons from getting absorbed into the system [source: Mayo Clinic].