Most cases of food poisoning last between one and three days, though the exact timeline depends on which germ caused it. Some types clear up in under 24 hours, while others can stretch to a week or more. Knowing what to expect at each stage helps you manage symptoms at home and recognize when something more serious is going on.
Timeline by Type of Contamination
Food poisoning isn’t one illness. It’s a catch-all term for dozens of different infections and toxins, each with its own clock. The fastest to hit and the fastest to resolve is staph-related food poisoning, which starts within 30 minutes to 8 hours of eating contaminated food and typically clears within 24 hours. This is the type most often linked to foods left out at room temperature too long, like potato salad or deli meats.
Norovirus, the most common cause of foodborne illness, takes a bit longer to appear. Symptoms usually show up 12 to 48 hours after exposure, and most people feel better within one to three days. Salmonella has a wider window: it can start anywhere from 6 to 48 hours after eating contaminated food, and diarrhea and fever often persist for four to seven days. E. coli O157:H7, the strain linked to serious outbreaks, has a longer incubation period of three to four days and can cause severe, often bloody diarrhea that lasts a week or longer.
At the extreme end, Hepatitis A from contaminated food may not cause symptoms for two to seven weeks, and the resulting illness (jaundice, fatigue, nausea) can last weeks to months. This is rare compared to the common culprits, but it illustrates why “food poisoning” doesn’t have a single answer.
What the First 24 to 72 Hours Look Like
Regardless of the specific germ, the early phase follows a predictable pattern: nausea and vomiting come first, followed by diarrhea and abdominal cramps. Fever may or may not be present. The worst of the vomiting usually passes within 12 to 24 hours, while diarrhea tends to linger a day or two longer. During this window, the biggest practical risk isn’t the infection itself. It’s dehydration.
Signs of dehydration include dark-colored urine, urinating much less than usual, extreme thirst, dizziness when you stand up, and fatigue. If you’re vomiting frequently, stick to small sips of water, broth, diluted fruit juice, or electrolyte drinks rather than trying to drink a full glass at once. Ice chips and popsicles work well when even sips feel like too much. Avoid caffeine and alcohol, which pull water out of your system faster.
When Symptoms Should Concern You
Most food poisoning resolves on its own, but certain signs mean you need medical attention. Call your doctor if diarrhea lasts more than three days, vomiting continues beyond two days, your fever reaches 101°F (38.3°C) or higher, you feel faint or confused, or your diarrhea turns bloody, black, or tarry. Watery diarrhea that becomes very bloody within the first 24 hours warrants emergency care, not just a phone call.
Pregnant women should contact their doctor at the first sign of fever with flu-like symptoms. Listeria infection, while uncommon, poses serious risks during pregnancy including miscarriage, stillbirth, and premature delivery. Intestinal listeria symptoms typically last one to three days, but the invasive form of the illness can develop within two weeks of exposure and requires prompt treatment. Older adults and people with weakened immune systems also face higher risks from listeria. In non-pregnancy cases of invasive listeriosis, nearly 1 in 6 people die.
Eating Again After Food Poisoning
Once the vomiting stops, you don’t need to wait a set number of hours before eating. The current guidance from gastroenterologists is to eat as tolerated rather than following a rigid timeline. That said, your stomach will handle smaller meals better than large ones, and bland, soft foods are easier to keep down in the first day or two.
Start with whatever appeals to you from the mild end of the spectrum: plain rice, toast, bananas, applesauce, crackers. As your stomach settles, add slightly more substantial options like scrambled eggs, skinless chicken, or cooked vegetables. The old “BRAT diet” (bananas, rice, applesauce, toast) isn’t wrong, but nutrition experts now say it’s too restrictive to follow strictly for more than a day. Your body needs protein and nutrients to recover, so branch out as soon as you can tolerate it.
How Long You Can Spread It
Feeling better doesn’t always mean you’re no longer contagious. Norovirus is notoriously easy to spread and can be shed in stool for two weeks or more after symptoms resolve. This is why handwashing matters even after you feel fine, especially before preparing food for others. Salmonella can also be shed for weeks after recovery in some people. If your job involves handling food, many local health departments require you to stay home for at least 24 to 48 hours after symptoms fully stop, and sometimes longer depending on the pathogen.
Lingering Gut Issues After Recovery
For most people, food poisoning is a miserable few days that ends cleanly. But a meaningful minority develop ongoing digestive symptoms that persist for months. Research from the Mayo Clinic found that roughly 1 in 5 people diagnosed with campylobacter infection (a common foodborne pathogen) went on to develop post-infectious irritable bowel syndrome. Symptoms include cramping, bloating, and altered bowel habits that meet formal diagnostic criteria for IBS, appearing six to nine months after the original infection.
This doesn’t mean every bout of food poisoning leads to chronic problems. But if you notice that your digestion doesn’t feel quite right weeks after your illness has passed, it’s worth mentioning to your doctor. Post-infectious IBS is a recognized condition with its own management strategies, and knowing the connection to a prior infection can speed up getting the right help.