Diagnosis

Food poisoning is often diagnosed based on a detailed history, including how long you've been sick, your symptoms and specific foods you've eaten. Your doctor will also perform a physical exam, looking for signs of dehydration.

Depending on your symptoms and health history, your doctor may conduct diagnostic tests, such as a blood test, stool culture or examination for parasites, to identify the cause and confirm the diagnosis.

For a stool culture, your doctor will send a sample of your stool to a laboratory, where a technician will try to identify the infectious organism. If an organism is found, your doctor likely will notify your local health department to determine if the food poisoning is linked to an outbreak.

In some cases, the cause of food poisoning can't be identified.

Treatment

Treatment for food poisoning typically depends on the source of the illness, if known, and the severity of your symptoms. For most people, the illness resolves without treatment within a few days, though some types of food poisoning may last longer.

Treatment of food poisoning may include:

  • Replacement of lost fluids. Fluids and electrolytes — minerals such as sodium, potassium and calcium that maintain the balance of fluids in your body — lost to persistent diarrhea need to be replaced. Some children and adults with persistent diarrhea or vomiting may need hospitalization, where they can receive salts and fluids through a vein (intravenously), to prevent or treat dehydration.
  • Antibiotics. Your doctor may prescribe antibiotics if you have certain kinds of bacterial food poisoning and your symptoms are severe. Food poisoning caused by listeria needs to be treated with intravenous antibiotics during hospitalization. The sooner treatment begins, the better. During pregnancy, prompt antibiotic treatment may help keep the infection from affecting the baby.

    Antibiotics will not help food poisoning caused by viruses. Antibiotics may actually worsen symptoms in certain kinds of viral or bacterial food poisoning. Talk to your doctor about your options.

Adults with diarrhea that isn't bloody and who have no fever may get relief from taking the medication loperamide (Imodium A-D) or bismuth subsalicylate (Pepto-Bismol). Ask your doctor about these options.

Lifestyle and home remedies

Food poisoning often improves without treatment within 48 hours. To help keep yourself more comfortable and prevent dehydration while you recover, try the following:

  • Let your stomach settle. Stop eating and drinking for a few hours.
  • Try sucking on ice chips or taking small sips of water. You might also try drinking clear soda, clear broth or noncaffeinated sports drinks, such as Gatorade. You're getting enough fluid when you're urinating normally and your urine is clear and not dark.
  • Ease back into eating. Gradually begin to eat bland, low-fat, easy-to-digest foods, such as soda crackers, toast, gelatin, bananas and rice. Stop eating if your nausea returns.
  • Avoid certain foods and substances until you're feeling better. These include dairy products, caffeine, alcohol, nicotine, and fatty or highly seasoned foods.
  • Rest. The illness and dehydration can weaken and tire you.

Preparing for your appointment

If you or your child needs to see a doctor, you'll likely see your primary care provider first. If there are questions about the diagnosis, your doctor may refer you to an infectious disease specialist.

What you can do

Preparing a list of questions will help you make the most of your time with your doctor. Some questions to ask include:

  • What's the likely cause of the symptoms? Are there other possible causes?
  • Is there a need for tests?
  • What's the best treatment approach? Are there alternatives?
  • Is there a need for medication? If yes, is there a generic alternative to the medicine you're prescribing?
  • How can I ease the symptoms?

What to expect from your doctor

Some questions the doctor may ask include:

  • Has anyone in your family or otherwise close to you developed similar symptoms? If so, did you eat the same things?
  • Have you traveled anywhere where the water or food might not be safe?
  • Are you having bloody bowel movements?
  • Do you have a fever?
  • Had you taken antibiotics in the days or weeks before your symptoms started?
  • When did symptoms begin?
  • Have the symptoms been continuous, or do they come and go?
  • What foods have you eaten in the past few days?

What you can do in the meantime

Drink plenty of fluids. Stick with bland foods to reduce stress on your digestive system. If your child is sick, follow the same approach — offer plenty of fluids and bland food. If you're breast-feeding or using formula, continue to feed your child as usual.

Ask your child's doctor if giving your child an oral rehydration fluid (Pedialyte, Enfalyte, others) is appropriate. Older adults and people with weakened immune systems might also benefit from oral rehydration solutions. Medications that help ease diarrhea generally aren't recommended for children.

July 15, 2017
References
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  3. Acheson DWK. Patient information: Food-poisoning (foodborne illness). http://www.uptodate.com/home. Accessed Jan. 31, 2017.
  4. Foodborne illness. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/foodborne-illnesses. Accessed Jan. 31, 2017.
  5. The big thaw — Safe defrosting methods for consumers. Food Safety and Inspection Service. https://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/the-big-thaw-safe-defrosting-methods-for-consumers/CT_Index. Accessed Jan. 31, 2017.
  6. Wanke CA. Approach to the adult with acute diarrhea in resource-rich settings. http://www.uptodate.com/home. Accessed Jan. 31, 2017.
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