Most stomach bugs are caused by viruses, which means there’s no pill that kills the infection itself. The best medicine for a stomach bug focuses on managing symptoms like diarrhea, nausea, body aches, and fever while your body fights off the virus, typically over one to three days. Staying hydrated matters more than any medication you can take.
Hydration Comes Before Any Medication
The biggest risk from a stomach bug isn’t the virus. It’s dehydration from losing fluids through vomiting and diarrhea. Replacing water alone isn’t enough because you’re also losing electrolytes like sodium and potassium that your body needs to function. Oral rehydration solutions (sold as Pedialyte, DripDrop, or generic store brands) contain the right balance of salts and sugars to help your intestines absorb fluid efficiently. The World Health Organization has recommended a specific low-concentration formula since 2003 that outperforms older versions.
If you don’t have a rehydration solution on hand, sip small amounts of clear broth, diluted juice, or sports drinks. Take small, frequent sips rather than gulping large amounts, especially if you’re still vomiting. Signs that dehydration is getting serious include a rapid pulse, no urination for eight or more hours, dizziness when standing, and extreme fatigue. In infants, fewer than six wet diapers a day is a red flag.
Over-the-Counter Diarrhea Relief
Two common options line pharmacy shelves for diarrhea: loperamide (sold as Imodium) and bismuth subsalicylate (sold as Pepto-Bismol or Kaopectate). Both work, but they’re not equal. In a head-to-head comparison, loperamide provided faster and more effective relief. It significantly reduced the number of unformed bowel movements, controlled diarrhea for longer after the first dose, and shortened the time to the last unformed stool. Patients also rated their overall relief significantly higher with loperamide at the 24-hour mark. Both were well tolerated with only minor side effects.
Loperamide works by slowing the movement of your intestines, giving them more time to absorb water from stool. Bismuth subsalicylate has a milder effect but also helps with nausea and stomach upset, making it a reasonable choice if your symptoms are more about queasiness than frequent trips to the bathroom. You can use either one for short-term symptom control in adults.
One important safety note: bismuth subsalicylate contains a compound related to aspirin. Do not give it to children under 16. In kids recovering from a viral illness, aspirin-related compounds carry a risk of Reye’s syndrome, a rare but serious condition that causes liver failure and brain damage. Loperamide also isn’t appropriate for very young children without a pediatrician’s guidance.
Managing Fever and Body Aches
Acetaminophen (Tylenol) is generally the safer choice for fever and body aches during a stomach bug. Ibuprofen (Advil, Motrin) and other anti-inflammatory painkillers can irritate an already inflamed stomach lining and make nausea worse. The Mayo Clinic advises using ibuprofen sparingly, if at all, when you have gastroenteritis.
That said, use acetaminophen carefully too, particularly in children, since it can stress the liver. Stick to the dose on the label and avoid combining it with other products that contain acetaminophen (many cold and flu remedies include it).
Why Antibiotics Won’t Help
Stomach bugs are overwhelmingly viral, caused by norovirus, rotavirus, or similar pathogens. Antibiotics only kill bacteria, so they do nothing against a viral infection. Taking them anyway isn’t just pointless. It’s actively risky. Antibiotics strip away the protective bacteria in your gut, which can open the door to a secondary infection with Clostridioides difficile, a bacterium that causes severe, sometimes dangerous diarrhea. The CDC notes that inappropriate antibiotic use also increases your risk of carrying antibiotic-resistant bacteria.
Do Probiotics Actually Help?
Probiotics are widely marketed for gut health, and Lactobacillus rhamnosus GG (sold as Culturelle) had the most evidence behind it for gastroenteritis. But a rigorous study at Cincinnati Children’s Hospital put it to the test and found no benefit. Children who took the probiotic twice daily for five days recovered at exactly the same rate as children who took a placebo. Diarrhea lasted about two days in both groups, and kids missed the same amount of daycare.
The researchers tested every subgroup they could think of: infants versus toddlers, viral versus bacterial causes, patients who had taken antibiotics, and patients at different stages of illness. They even independently verified the probiotic’s purity and strength. Every analysis reached the same conclusion. If you want to take a probiotic, it’s unlikely to cause harm, but don’t count on it to speed your recovery.
Zinc for Children With Diarrhea
The WHO recommends zinc supplementation for children with acute diarrhea. The standard dose is 20 mg per day for 10 to 14 days, or 10 mg per day for infants under six months. Zinc helps reduce stool frequency and volume in young children and is especially emphasized in low- and middle-income countries where diarrheal illness is a leading cause of child mortality. For adults in well-nourished populations, zinc supplementation during a stomach bug is less studied and not a standard recommendation.
What to Eat (and Avoid) While Recovering
For the first several hours of active vomiting, don’t force food. Focus on sips of clear fluids. Once you can keep liquids down, ease back in with bland, easy-to-digest foods: plain rice, toast, bananas, applesauce, crackers, or simple broth. These give your digestive system something to work with without overwhelming it.
Avoid dairy products, fatty or fried foods, caffeine, and alcohol until you’ve been symptom-free for at least a day. Dairy is particularly tricky because a stomach bug can temporarily reduce your ability to digest lactose, which can restart diarrhea even after the virus is gone. Sugary drinks and fruit juices at full strength can also pull water into the intestines and worsen diarrhea.
Signs That Something More Serious Is Happening
Most stomach bugs resolve on their own within one to three days. But certain symptoms suggest you need medical attention. In adults, watch for blood in your vomit or stool, a fever above 104°F (40°C), an inability to keep any fluids down for more than 24 hours, severe abdominal pain, or signs of serious dehydration like a rapid pulse with low blood pressure and little to no urination. In young children and infants, lethargy (sleeping far more than usual, unresponsive to play), no wet diapers for eight hours, or a sunken soft spot on an infant’s head all warrant immediate care.