Gastroenteritis is inflammation of the lining of the stomach and small and large intestines. Although it is usually caused by infection with a microorganism, it can also be caused by ingesting drugs, medications, or chemicals.
(See also Overview of Gastroenteritis.)
Drugs and Medications
Nausea, vomiting, and diarrhea are common side effects of many drugs and medications. Common offenders include
Antacids containing magnesium as a major ingredient
Antibiotics
Chemotherapy drugs
Immunotherapy
Radiation therapy
Medications used to treat internal parasitic worms
Laxatives
Antibiotic use also may cause Clostridioides difficile–induced diarrhea.
Laxative abuse can lead to weakness, vomiting, diarrhea, electrolyte loss, and other disturbances.
Recognizing that a drug or medication is causing gastroenteritis can be difficult. In mild cases, a doctor can have a person stop taking the drug or medication and later start taking it again. If the symptoms subside when the person stops taking the drug or medication and resume when the person starts taking it again, it may be the cause of the gastrointestinal symptoms. In severe cases of gastroenteritis, a doctor may instruct the person to stop taking the drug or medication permanently.
Chemicals
Gastroenteritis may result from ingesting chemical toxins (see Overview of Food Poisoning). These toxins are usually produced by a plant, such as poisonous mushrooms, or by certain kinds of seafood and thus are not the product of an infection.
Gastroenteritis due to chemical toxicity can also occur after ingesting water or food contaminated by chemicals such as arsenic and heavy metals such as lead, mercury, or cadmium or after directly eating or swallowing a chemical or metal. Heavy-metal poisoning frequently causes nausea, vomiting, abdominal pain, and diarrhea.
Doctors ask about recent contact with contaminated food or water or with heavy metals. Sometimes gastroenteritis can be traced to contaminated water or inadequately cooked, spoiled, or contaminated food. People who have ingested a heavy metal may have a blood test to determine the level of metal that is in the blood.
Treatment
Rehydration
Usually the only treatment needed for gastroenteritis, including gastroenteritis caused by drugs, medications, or chemicals, is getting bed rest and drinking an adequate amount of fluid. Even a person who is vomiting should drink as much as can be tolerated, taking small frequent sips.
If vomiting or diarrhea is prolonged or the person becomes severely dehydrated, fluids and electrolytes given by vein (intravenously) may be needed.
Because children can become dehydrated more quickly, they should be given fluids with the appropriate mix of salts and sugars. Any of the commercially available solutions designed to replace lost fluids and electrolytes (called oral rehydration solutionsbreastfeeding should continue.
As the symptoms subside, the person may gradually add foods to the diet. There is no need to limit the diet to bland foods such as cereal, gelatin, bananas, rice, applesauce, and toast. However, some people are unable to tolerate milk products for a few days after having diarrhea.
