A drug used for its effects on the gastrointestinal system, e.g. controlling gastric acidity, regulating gastrointestinal motility and water flow, and improving digestion.
A drug used to prevent nausea or vomiting. An antiemetic may act by a wide range of mechanisms: it might affect the medullary control centres (the vomiting centre and the chemoreceptive trigger zone) or affect the peripheral receptors.