Important Covid-19 information
Request a Demo

Current News

How Long Does It Actually Take to Get Food Poisoning From a Sketchy Meal?

When food poisoning hits, you basically need to camp out by the toilet. Stray too far, and, well, you might be sorry.

Food poisoning occurs when you eat contaminated food, which can result in a whole host of gastrointestinal symptoms.

"The signs and symptoms are usually abdominal cramps, nausea with or without vomiting, and diarrhea," says John Pandolfino, M.D., chief of gastroenterology and hepatology at Northwestern Memorial Hospital. This includes feeling weak and fatigued, and could also include fever and chills.

It's not always 'exotic' foods that cause food poisoning. Often, it's caused by your food handler, a contaminated kitchen, or a contaminated source, like the fields where your food was grown.

When it comes to determining the source of your food poisoning, it can be tricky to narrow down. But let's look at a few common culprits.


Bacteria like Campylobacter, E. coli, and Salmonella are the most common cause of bacterial food borne illness, says Dr. Pandolfino.

"They can take from one day to a week before they manifest and are usually the ones associated with (undercooked) meat and poultry, but can also be associated with unpasteurized milk and egg yolks," he says.

Symptoms include stomach cramps, diarrhea—which can be bloody—and vomiting. Treatment is usually just rest and hydration. Your doctor likely won’t prescribe antibiotics for these infections, as they can increase the risk of complications (and prolong symptoms.) You also should avoid taking anti-diarrheal medications like Imodium because they can slow down your digestive system, which can prolong your body from getting rid of the toxins.


This parasite's source is...poop. Usually from the soil, food, or water that's been infected with human or animal feces.

You can get Giardia through eating contaminated food—say, if your food handler didn’t wash his hands, or if your produce has been washed with contaminated water—swallowing contaminated water, or even direct contact with an infected person.

On average, you come down with giardiasis about seven days after exposure, though its incubation period can range from one to 14 days, according to the Centers for Disease Control and Prevention (CDC).

Symptoms of giardiasis include diarrhea, gas, greasy stool, upset stomach, and dehydration, the CDC says.

"It can last 2 weeks or more," says Dr. Pandolfino. Your doctor may have you provide a stool sample to see if Giardia is to blame, and if so, you may be treated with prescription meds like metronidazole, tinidazole, and nitazoxanide.


Vibrio—which causes an illness called vibriosis—is a bacteria that infects uncooked or undercooked shellfish, says Dr. Pandolfino. Oysters in particular are particularly risky, says the CDC.

Symptoms usually occur within 24 hours after eating the infected food, according to the CDC, but they can sometimes take a week to appear, says Dr. Pandolfino. These include watery diarrhea, cramping, nausea, fever, and chills.

Most infections occur from May to October, when waters are warmer, and people with liver disease are at greatest risk. Still, most people with a mild case of the bacterial illness will get better in about three days.


"Norovirus is quite common and can be associated with symptoms within 12 hours to 48 hours,” says Dr. Pandolfino. It causes diarrhea, nausea, and stomach pain.

It's one of the most contagious viruses around, and a source of major food poisoning outbreaks. Plus, there are many different types of norovirus, and getting sick with one kind doesn’t necessarily protect you from getting another type down the line, the CDC says.

Norovirus can be seen in uncooked shellfish, says Dr. Pandolfino, if their source has become contaminated. It’s also often seen in ready-to-eat foods, like raw fruits or vegetables, if they’ve been handled by someone who’s sick with the virus.

Most people with the illness get better within about one to three days—antibiotics won’t help, since it’s not a bacterial infection.


When it comes to a Staph infection, you usually think of a skin infection, not food poisoning. We all carry it on our skin and in our noses, but it becomes dangerous if it enters the body.

"Foods contaminated with Staph aureus include meats and is also associated with (dairy) cream sauces or salad dressings," says Dr. Pandolfino.

You most likely will pick this up from the person who prepared your food, though. Symptoms—vomiting, nausea, stomach cramps, and diarrhea—start between 30 minutes to 6 hours after ingesting, and usually last only one day.


The biggest issue with food poisoning is often dehydration, since your body is expelling fluids (as well as sodium and electrolytes) rapidly—yep, when you’re vomiting or projectile pooping.

For that reason, don't stick to just plain drinking water.

"Stay well hydrated—use sport drinks that do not have caffeine," says Dr. Pandolfino, since caffeine is a diuretic, which can make your dehydration even worse.

It's important to keep taking in calories to help your body function properly. So stick with a plain, easily digestible diet.

"You should eat a bland diet—think crackers, bread/toast, bananas and rice are staples. Stay away from dairy and fried/fatty foods," says Dr. Pandolfino, which are harder on your body to digest.

If you experience bloody diarrhea, high fevers over 101.5 Fahrenheit, a change in mental functioning, or if your symptoms last more than three days, you should seek medical attention, he says. It’s possible you may need treatment like antibiotics, though they are usually reserved for people with severe symptoms.