Many drugs and medications cause nausea, vomiting, and diarrhea as adverse effects. A detailed drug and medication history must be obtained. In mild cases, cessation followed by reuse of the drug may establish a causal relationship. Commonly responsible drugs include antacids containing magnesium, antibiotics, antihelminthics, cytotoxics (used in cancer therapy), colchicine, digoxin, heavy metals, laxatives, immunotherapy, and radiation therapy. Use of antibiotics may lead to Clostridioides difficile–induced diarrhea. Diarrhea and other symptoms in C. difficile infection may be more severe than antibiotic-associated diarrhea and persist after completion or cessation of antibiotics.
Iatrogenic, accidental, or intentional heavy-metal poisoning frequently causes nausea, vomiting, abdominal pain, and diarrhea.
Laxative abuse, sometimes denied by patients, may lead to weakness, vomiting, diarrhea, electrolyte depletion, and metabolic disturbances. Stool testing, specifically for stool osmolality, can help differentiate diarrhea resulting from osmotic laxative abuse from diarrhea resulting from other causes.
(See also Overview of Gastroenteritis.)
