Fundamentally, decontamination seeks to prevent drug absorption - some techniques may also enhance elimination.
The decision to decontaminate is in essence a risk/benefit assessment. When the risk of decontamination is very low such as washing after a dermal exposure of a toxic compound there is relatively little controversy. This is not the case with Gastrointestinal Decontamination, which is one of the most hotly debated areas in clinical toxicology. Decisions include whether to do it at all and if so which type of decontamination should be used. The potential choices are described below. You should be aware that for a number of the choices there is significant technical variation in clinical practice and therefore in the literature. For example gastric lavage has been described with various sizes of tubes, various amounts and types of lavage fluid. You could also consider the potential cost of these procedures which can be measured in both consumables and staff time.
In general any potential benefit from gastrointestinal decontamination is very reduced once 2 hours from the ingestion has elapsed.
The risk of the procedure increases markedly as the patients GSC (level of consciousness) decreases.