For a basic upset stomach, an antacid like calcium carbonate (Tums) works fastest for heartburn and acid-related discomfort, while bismuth subsalicylate (Pepto-Bismol) covers the widest range of symptoms including nausea, bloating, and diarrhea. What you should reach for depends on exactly what kind of stomach trouble you’re dealing with, so it helps to match your symptoms to the right remedy.
Acid-Related Discomfort
If your upset stomach feels like burning, sourness, or pressure in your upper abdomen or chest, the problem is likely excess stomach acid. Chewable antacids containing calcium carbonate neutralize acid on contact and bring relief within minutes. They’re the fastest option but wear off relatively quickly, usually within an hour or two.
For longer-lasting relief, acid reducers like famotidine (Pepcid) work differently. Instead of neutralizing acid that’s already there, they reduce how much acid your stomach produces in the first place. The tradeoff is a slower onset (30 to 60 minutes) but effects that last up to 12 hours. If you’re dealing with recurring heartburn or indigestion that keeps coming back through the day, an acid reducer is the better choice.
Proton pump inhibitors like omeprazole (Prilosec) are the strongest acid suppressors available over the counter. They keep stomach pH elevated for 15 to 22 hours daily. But they take one to four days to reach full effect, so they’re not useful for occasional stomach upset. They’re designed for frequent heartburn that happens two or more days per week.
Nausea, Bloating, and Diarrhea
Bismuth subsalicylate, the active ingredient in Pepto-Bismol and Kaopectate, is the go-to for the more general “I feel sick to my stomach” experience. It coats the stomach lining, reduces inflammation, and has mild antibacterial properties, which makes it useful for nausea, indigestion, and mild diarrhea all at once.
One important caution: bismuth subsalicylate contains a compound related to aspirin. If you have an aspirin allergy, asthma with nasal polyps, or a condition called aspirin-exacerbated respiratory disease, avoid it entirely. It can trigger severe respiratory reactions in sensitive individuals. Children and teenagers recovering from flu or chickenpox should also skip it due to the risk of Reye’s syndrome.
For diarrhea specifically, loperamide (Imodium) slows gut contractions and can stop loose stools faster than bismuth products. It won’t help with nausea or upper stomach discomfort, though, so it’s a more targeted tool.
Ginger for Nausea
Ginger is one of the few natural remedies with solid clinical backing for stomach upset, particularly nausea. Its active compounds, gingerols and shogaols, block serotonin receptors in the gut that trigger the urge to vomit. This is the same pathway that some prescription anti-nausea drugs target.
Most clinical studies use doses around 1,000 mg daily, split into two or three portions. The European Medicines Agency recommends 500 mg three times daily for pregnancy-related nausea, and 1,000 mg taken an hour before travel for motion sickness. The FDA considers up to 4 grams daily to be safe, though most people don’t need that much. You can get effective doses from ginger capsules, freshly grated ginger steeped in hot water, or even strong ginger chews. Ginger ale typically contains too little real ginger to help.
Peppermint for Cramping and Bloating
If your stomach upset involves cramping, pressure, or that uncomfortable “too full” feeling, peppermint oil can help. Menthol, its main active component, relaxes the smooth muscle lining your digestive tract by blocking calcium channels that trigger contractions. This eases spasms and helps trapped gas move through.
Enteric-coated peppermint oil capsules are the preferred form. The coating prevents the capsule from dissolving in your stomach, which matters for two reasons: it delivers the oil further down the digestive tract where cramping often occurs, and it reduces the chance of triggering acid reflux. Without the coating, peppermint oil can relax the valve between your stomach and esophagus, making heartburn worse. Peppermint tea is gentler and fine for mild bloating, but it delivers a much lower dose than capsules.
What to Eat and Drink
You’ve probably heard of the BRAT diet: bananas, rice, applesauce, and toast. It’s fine for a day or two when your stomach is at its worst, but there’s no research showing it speeds recovery, and it’s nutritionally limited. A broader approach works just as well. Brothy soups, oatmeal, boiled potatoes, crackers, and unsweetened dry cereal are all easy to digest and give your body more to work with.
Once the worst has passed, typically after 24 to 48 hours, start adding foods with more nutritional value: cooked squash, carrots, sweet potatoes without skin, avocado, skinless chicken, fish, and eggs. These are still gentle on the stomach but provide the protein and nutrients your body needs to recover. Avoid fried foods, dairy, caffeine, and alcohol until you’re feeling consistently better.
Staying hydrated matters more than eating, especially if you’ve been vomiting or having diarrhea. Small, frequent sips of water or a commercial oral rehydration solution (like Pedialyte) are more effective than drinking large amounts at once. The World Health Organization recommends using pre-made rehydration products rather than homemade sugar-salt mixtures, since getting the proportions wrong can actually worsen dehydration.
Probiotics After a Stomach Bug
If your upset stomach is from a stomach flu or food poisoning, probiotics can shorten the duration of diarrhea by roughly one day. Not all strains are equal, though. A large evidence review in children found that Saccharomyces boulardii (a beneficial yeast sold as Florastor) and Limosilactobacillus reuteri showed the strongest effects on reducing how long diarrhea lasted. Multi-species probiotic blends also performed well.
Interestingly, Lactobacillus rhamnosus, one of the most widely marketed probiotic strains, did not significantly shorten diarrhea duration in the same analysis, though it did help more children fully recover by the end of treatment. And one strain, Lactobacillus casei, was actually associated with slightly longer diarrhea. If you’re choosing a probiotic specifically for an acute stomach illness, the strain on the label matters.
Signs That Need Medical Attention
Most upset stomachs resolve on their own within a few days. But certain patterns signal something more serious. Sudden, severe abdominal pain that doesn’t ease within 30 minutes warrants emergency care. So does abdominal pain paired with continuous vomiting, high fever, or a rapid pulse.
Pain concentrated in the lower right abdomen, especially with loss of appetite and fever, can indicate appendicitis. Pain in the middle upper abdomen that worsens after eating and lasts for days, combined with nausea and a swollen or tender belly, may point to pancreatitis. Bloody vomit, bloody or black stools, and signs of dehydration (dizziness, dark urine, no urination for many hours) also call for prompt medical evaluation rather than home treatment.