Most food poisoning resolves on its own within one to three days, and the best “medicine” for most cases is staying hydrated and managing symptoms while your body clears the infection. Over-the-counter options can help with diarrhea and nausea, but some situations call for prescription treatment or a trip to the emergency room. Here’s what actually works and when to use it.
Over-the-Counter Medicines for Diarrhea
Two widely available medications can help control diarrhea from food poisoning: loperamide (sold as Imodium) and bismuth subsalicylate (the active ingredient in Pepto-Bismol and Kaopectate). Loperamide slows down gut contractions, giving your intestines more time to absorb water and reducing the frequency of loose stools. Bismuth subsalicylate works differently, coating the stomach lining and reducing inflammation in the digestive tract while also having mild antimicrobial effects.
There is one critical rule: do not take either of these if you have a fever or bloody diarrhea. These are signs of a more invasive bacterial infection, and slowing down your gut can actually trap the harmful bacteria inside longer. With certain strains of E. coli, using anti-diarrheal medication can increase the risk of a serious kidney complication called hemolytic uremic syndrome. Bismuth subsalicylate should also not be given to children under 12, and neither medication is considered safe for infants or young children without a doctor’s guidance.
Managing Nausea and Vomiting
If vomiting is your main symptom, over-the-counter options are more limited. Bismuth subsalicylate can help with mild nausea, but for intense vomiting, doctors sometimes prescribe ondansetron (Zofran). This is an anti-nausea drug originally developed for chemotherapy patients that blocks the signals in your brain and gut that trigger the vomiting reflex.
Clinical trials show ondansetron works fast. In studies of patients with acute gastroenteritis, those who took it were about 50% more likely to stop vomiting within the first hour compared to a placebo. It also cut the need for IV fluids roughly in half. While ondansetron is sometimes used off-label for vomiting from stomach bugs, especially in emergency departments for children, it requires a prescription. If you can’t keep any fluids down for more than a few hours, that’s a reason to call your doctor and ask about it.
Pain Relief That Won’t Make Things Worse
When food poisoning comes with body aches, cramping, or a low fever, reaching for a painkiller is natural. Acetaminophen (Tylenol) is the safer choice here. It eases pain and reduces fever without irritating your stomach. NSAIDs like ibuprofen (Advil, Motrin) and naproxen (Aleve) are known to cause stomach upset even under normal circumstances. When your digestive tract is already inflamed from an infection, adding an NSAID on top can make nausea, cramping, and stomach irritation significantly worse.
When Antibiotics Are Needed
Most food poisoning is caused by viruses or mild bacterial infections that your immune system handles without help. Antibiotics don’t work against viruses at all, and for many bacterial causes like Salmonella, antibiotics aren’t recommended for otherwise healthy adults because they don’t shorten the illness and can disrupt your gut bacteria further.
Doctors consider antibiotics when the illness is severe: a high fever, bloody stool, more than eight episodes of liquid diarrhea per day, symptoms lasting longer than a week, or signs that hospitalization might be needed. People who are very young, over 50, pregnant, or have weakened immune systems are also more likely to need antibiotic treatment. The specific antibiotic depends on the bacteria involved. Campylobacter, one of the most common culprits, is typically treated with a macrolide antibiotic. Shigella and certain E. coli strains respond to different classes of drugs. Your doctor will often start with an empiric antibiotic while waiting for stool culture results, then adjust if needed.
Traveler’s diarrhea is one scenario where antibiotics are used more liberally. The most common cause, a toxin-producing strain of E. coli, responds well to a short course of antibiotics and can cut a miserable trip significantly shorter.
Rehydration: The Most Important Treatment
No medicine matters as much as replacing the fluids and electrolytes you’re losing through vomiting and diarrhea. Dehydration is the most common complication of food poisoning, and it can become dangerous quickly, especially in children and older adults. Oral rehydration solutions like Pedialyte are more effective than water alone because they contain the right balance of salts and sugars to help your intestines absorb fluid efficiently.
Sip small amounts frequently rather than trying to drink a full glass at once, which can trigger more vomiting. Sports drinks are better than nothing but contain more sugar and less sodium than ideal. Broth is another reasonable option.
Watch for signs that dehydration is getting ahead of you: extreme thirst, dark urine, urinating much less than usual, dizziness when standing, sunken eyes, or skin that stays “tented” when you pinch it instead of flattening back quickly. If you notice these, or if you simply can’t keep fluids down, you may need IV fluids at an urgent care or emergency room.
Probiotics for Recovery
Probiotics won’t cure food poisoning, but certain strains may help your gut recover faster afterward. The yeast-based probiotic Saccharomyces boulardii has the strongest evidence. It was the first yeast studied as a probiotic for human medicine, and reviews have found it significantly more effective than other common probiotic strains at preventing traveler’s diarrhea. It also shows promise for restoring healthy gut bacteria after infections and antibiotic use. You can find it in supplement form at most pharmacies. Starting it during or shortly after your illness is reasonable, though it’s a supporting player, not a primary treatment.
What Doesn’t Work: Activated Charcoal
Activated charcoal has gained popularity as a “detox” remedy, and some people take it for food poisoning hoping it will absorb the toxins. The reality is less promising. While activated charcoal is used in hospitals for certain types of acute poisoning (swallowed pills, for example), clinical toxicologists do not recommend at-home use. It only works when taken very shortly after ingesting a poison, and it’s ineffective against the kinds of bacterial toxins and viral infections that cause food poisoning. As one clinical toxicologist at the Utah Poison Control Center put it, there “really isn’t any reliable evidence” supporting charcoal’s supposed digestive benefits, and no large studies back these claims.
A Quick Reference by Symptom
- Diarrhea without fever or blood: Loperamide or bismuth subsalicylate, plus oral rehydration
- Nausea and mild stomach upset: Bismuth subsalicylate
- Severe vomiting: Ask your doctor about ondansetron
- Body aches or low fever: Acetaminophen
- Bloody diarrhea, high fever, or severe symptoms: Skip the OTC anti-diarrheals and contact a doctor, as you may need antibiotics or IV fluids