Caustic ingestion occurs when someone accidentally or deliberately ingests a caustic or corrosive substance. Depending on the nature of the substance, the duration of exposure and other factors it can lead to varying degrees of damage to the oral mucosa, the esophagus, and the lining of the stomach. Caustic ingestion occurs when someone accidentally or deliberately ingests a caustic or corrosive substance. Depending on the nature of the substance, the duration of exposure and other factors it can lead to varying degrees of damage to the oral mucosa, the esophagus, and the lining of the stomach. The severity of the injury can be determined by endoscopy of the upper digestive tract, although CT scanning may be more useful to determine whether surgery may be required. During the healing process, strictures of the oesophagus may form, which may require therapeutic dilatation and insertion of a stent.