## **Core Concept**
Gastric lavage, also known as stomach pumping, is a procedure where the stomach is flushed of its contents. It's a treatment sometimes used in cases of poisoning. The effectiveness and indications for gastric lavage depend on the type of poison ingested and the timing of the procedure.

## **Why the Correct Answer is Right**
The correct answer involves a specific poison where gastric lavage is beneficial even if the poisoning route is not oral (parenteral). In cases of poisoning by certain substances that can be metabolized into toxic compounds or have a enterohepatic circulation, gastric lavage can still be useful. Specifically, for poisoning with **D. Lithium**, gastric lavage may be considered even if the ingestion wasn't oral because lithium can cause significant gastrointestinal symptoms and its elimination can be enhanced through gut decontamination.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because for most corrosive substances, the primary concern is the damage to the esophagus and stomach. Gastric lavage is generally contraindicated in corrosive poisoning due to the risk of perforation.
- **Option B:** This option is incorrect because, in most cases of hydrocarbon poisoning, the treatment focuses on supportive care. Gastric lavage is not typically recommended due to the risk of aspiration and minimal benefit.
- **Option C:** This option is incorrect as well; for most organic compounds or solvents, the approach is supportive care rather than aggressive gastrointestinal decontamination like gastric lavage.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that gastric lavage is most effective when performed shortly after ingestion and is generally not recommended for routine use in most poisonings due to limited benefit and potential complications. However, certain substances like **lithium** may still benefit from gastric lavage even if the route of poisoning wasn't oral, due to its pharmacokinetics.

## **Correct Answer: D. Lithium.**