Gastroenteritis - Upset Stomach

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Gastroenteritis is an inflammation of the stomach lining and intestines. Most gastroenteritis is caused by common viruses and can be treated at home. Sometimes, however, gastroenteritis is caused by parasites; bacteria such as Shigella, Salmonella, Campylobacter, and E. coli; allergic reactions to certain foods; or irritation from too much alcohol.


  • nausea or vomiting
  • loose or liquid stools
  • increased number of stools
  • headache or body aches
  • chills, with or without fever
  • cramping abdominal pain


Most people with gastroenteritis can successfully treat their symptoms at home. Treatment is aimed at fluid replacement and dietary management. Antibiotics only help if the cause is bacteria, not a virus.

During the first 24 to 36 hours of illness, the best treatment is a diet of clear liquids only. Avoid solid food, alcohol, and caffeine during this period. Frequent, small amounts of clear liquids are best and should add up to at least two to three liters per day. If vomiting occurs, wait one to two hours after vomiting and try a few sips of water or ice chips. If these are tolerated, progress to other clear liquids, such as:

  • water
  • sports drinks
  • clear, non-caffeinated sodas such as 7-Up, Sprite, or ginger ale
  • powdered fruit-flavored drinks (e.g., Kool-Aid)
  • diluted juices (apple, grape, cherry, or cranberry; avoid citrus juices like orange or lemon)
  • clear broth or bouillon
  • decaffeinated tea
  • popsicles
  • gelatin diluted with water


  • Acetominophen (650 mg) may be taken every 4 hours to control fever, headaches, and body aches. Aspirin and ibuprofen can cause stomach irritation and should be avoided.
  • Bismuth subsalicylate (e.g., Pepto-Bismol, 30 to 60 ml or 2 tablespoons) may be taken every 30 minutes, for a total of 8 doses, to control diarrhea. Possible side effects include black stool or tongue, nausea, or constipation. Do not take bismuth subsalicylate if you are taking aspirin, other subsalicylates, doxycycline, anticoagulants, probenecid, or methotrexate.
  • Loperamide hydrochloride (e.g., Imodium A-D, 2 caplets or 4 teaspoons) slows intestinal movement and may be taken after the first loose bowel movement. Take 1 caplet or 2 teaspoons for each bowel movement after the first. Do not exceed 4 caplets or 8 teaspoons in a 24-hour period.


After nausea, vomiting, and diarrhea have been controlled with a clear liquid diet for 24 to 36 hours, start to add bland solids while continuing fluid intake. Some bland foods include:

  • toasted white bread with only honey or clear jelly
  • soda crackers
  • white rice (no butter)
  • Cream of Wheat or rice cereal (no milk)
  • applesauce or bananas
  • boiled potatoes
  • baked or broiled fish or poultry without skin or fat
  • cultured dairy products (e.g., yogurt, cottage cheese, buttermilk)

Gradually resume a usual diet after 24 to 48 hours of eating bland solids if symptoms improve. It may take several days before the bowels function normally.

Foods to avoid

Gastroenteritis causes an inflammation of the digestive tract. Avoid foods that may be irritating or could worsen inflammation, such as:

  • non-cultured dairy products (milk, cheese, ice cream)
  • spicy foods
  • greasy or fatty foods (e.g., cream soups, beef, pork)
  • alcohol or caffeine
  • foods containing roughage (whole grains, seeds and nuts, fruits with skins, raw vegetables)


  • Wash hands well with soap and water after using the bathroom and before eating or handling food.
  • Do not share eating or drinking utensils.
  • Avoid milk, meat, or egg-based foods that have not been refrigerated.
  • After preparing uncooked meat and poultry, thoroughly clean all utensils and work surfaces before using them with other foods.
  • When traveling in foreign countries, drink only bottled water or bottled drinks and eat only fruits and vegetables that can be peeled or that have been thoroughly cooked. Avoid sidewalk food stands.

When to consult a clinician

Contact a clinician if any of the following are experienced:

  • persistent abdominal pain, unrelieved by vomiting or passing a bowel movement
  • fever over 101°F, not relieved with acetaminophen
  • vomiting or diarrhea for more than 24 hours without improvement or more than three times an hour
  • blood in vomit or stools
  • no urination for more than eight hours

[HU450: Updated 05/08]