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What are Viral Gastroenteritis? Stomach Flu vs Food Poisoning

Food Poisoning Vs Stomach Flu
Medically reviewed by Dr. Mavra Farrukh


Were you out for dinner last night? Are you feeling sick (nausea), having diarrhea, vomiting, and stomach cramps that may be worsening with time, and are thinking about whether or not to reach out to a medical professional? This article is for you.

These symptoms usually confuse the patient making them wonder if it is food poisoning or stomach flu.

What is Food Poisoning? 

Ingestion of contaminated food leads to food poisoning also called food-borne illness. The symptoms usually present within a few hours compared to stomach flu (viral gastroenteritis) which usually takes about 24 to 72 hours to surface after exposure. Mostly food poisoning is mild and resolves on its own but if it persists you may need to consult a healthcare professional.

Contamination can occur at any point in food processing and production. Incorrectly cooked food or mishandling while food preparation in the kitchen can also lead to food poisoning.

What is Stomach Flu?

Viruses are mostly responsible for cases of stomach flu. These agents include

  • Rota viruses 
  • Caliciviruses, including noroviruses such as the Norwalk virus
  • Astroviruses
  • Enteric adenoviruses
  • less often Toroviruses
  • Coronaviruses
  • Picornaviruses (including the Aichi virus)
  • Pestiviruses.

 Rotaviruses and noroviruses are responsible for most non-bacterial cases of gastroenteritis.

Causes of Food Poisoning

  • consuming contaminated food or water
  • being in close contact with someone with the virus
  • sharing utensils or other items of use with someone who has the virus
  • touching contaminated surfaces
  • not washing hands properly and handling food 

Stomach flu can be acquired by ingesting contaminated food or sharing utensils, towels, or food with someone who has one of the viruses that cause the condition. It is usually caused by viruses (eg: Norovirus in Adults, Rotavirus in children) or non-invasive bacteria. Symptoms include watery, non-bloody diarrhea, mild, self-limiting disease, and resolves within 7 days.

Sometimes, you can get food poisoning without vomiting or food poisoning without diarrhea. Individuals may not have all or most of the symptoms.

What is the Difference Between Food Poisoning and Stomach Flu?

Symptoms and duration are key clues to the difference between stomach flu and food poisoning. 

Though food poisoning is common and may be self-limiting, it usually lasts longer. Whereas stomach flu symptoms have a shorter course duration. Food poisoning has an early onset within a few hours of food ingestion. Stomach flu or gastroenteritis may take up to 24 to 72 hours to develop. Organisms responsible for food poisoning include bacteria (E.Coli, Salmonella, Campylobacter) and viruses and parasites. 

What are the Symptoms of Stomach Infection?

The variation in symptoms of both diseases is listed below 

Common symptoms of Food poisoning:

  • Nausea 
  • Vomiting 
  • Diarrhea (can be associated with blood and mucous)
  • Severe abdominal cramping 
  • High-grade fever 
  • Duration of more than 7 days 
  • Worsening symptoms over time

In case you experience any of these please contact your doctor for further evaluation and investigation.  

Common Symptoms of Stomach Flu

  • Nausea 
  • Vomiting 
  • Sudden, water diarrhea 
  • Mil fever 
  • General malaise, lack of energy, and weakness 
  • Symptoms are usually short-lived, lasting to a weeks time
Are you Experiencing Nausea, Vomiting and Diarrhea? You may be having Food Poisoning. Talk to our doctor to find out

Diagnosis of Food Poisoning and the Stomach Flu?

Food poisoning and Stomach flu are often diagnosed by your doctor based on the history and symptoms. If the symptoms are mild and improve over a short period of time you might not require any tests.

Although if they persist, you need to consult a health care professional and might require investigations like stool or blood tests for diagnosis after an initial medical history and physical evaluation. An initial evaluation aims to distinguish mild disease from severe disease. 

1. Medical History

It is one of the important indicators of the cause of your stomach bug. Your doctor might ask questions about:

  • Your symptoms
  • Duration of symptoms 
  • Frequency of your symptoms 
  • About your last meals 
  • History of travel
  • Any history of contact with people experiencing similar symptoms
  • Any known medical conditions 
  • Medication history 

2. Physical Exam

Your doctor may check your:

  • Blood pressure 
  • Heart rate 
  • Temperature 
  • Examine the body for signs of dehydration
  • Abdominal examination 
  • At times a digital rectal exam may be performed to look for blood or mucous in stool which may be present with bacterial or parasitic infections

3. Stool Analysis

A stool analysis may be advised to detect viruses, bacteria, and parasites. 

4. Blood test

These are performed to look for signs of certain infections or dehydration. 

How to Recover from Food Poisoning and Stomach Flu?

The symptoms usually improve within a week most of the time, and you do not need to visit a doctor or seek professional help. 

Initially, it is advised just to treat it symptomatically and allow your body to naturally purge the digestive tract eliminating the harmful bacteria and keeping an eye on your hydration levels. This is the reason why an over-the-counter diarrhea medication is not considered initially to treat food poisoning. 

You can follow the following to help with your symptoms. 

1. Keep Yourself Well Hydrated

Try to drink plenty of water, even if you can only take a sip. Oral rehydration solutions (ORS) are advised especially for the elderly and those with other known medical conditions.

2. Eat Bland Foods

You may be wondering what to eat with stomach flu and food poisoning. Initially, a rest period for your stomach is advised, later eat bland foods when you feel like it, or in small portions. These may include:

  • Soups
  • Crackers 
  • Bananas 
  • Applesauce 
  • Rice  
  • Toast 

3. Avoid Foods that are Tough on the Digestive Tract

These may include:

  • Foods with high fiber content  
  • Dairy
  • Alcohol  
  • Spicy foods  
  • Caffeine 
  • Artificial sweeteners
  • High-fructose foods include grape juices, honey, dates, nuts, and figs 

4. Rest

Last but not least, get plenty of rest. Rest helps your body go into recovery mode and gives it time to heal itself.  

Follow these tips and they will make you feel better soon.

What is the treatment for food poisoning and stomach flu?

Most people usually recover at home on their own and do not require any further treatment. But if there are any red flag signs like persisting or worsening of symptoms your doctor might recommend following up depending upon your condition.

1. Intravenous Fluid Therapy

  • This is initiated in persons experiencing extreme vomiting and diarrhea leading to electrolyte disturbances to prevent dehydration.

2. Antibiotics

  • These are medications that work against the specific organisms causing the infection. But most people do not require these even if they have a bacterial infection. Usually, antibiotics for stomach infections are advised if you have a fever or blood or mucus in stool.

3. Anti Diarrheal Medications

  • Some people find taking antidiarrheal medications helpful. These include Loperamide (brand names: Diamode, Imodium), Diphenoxylate-atropine (brand name: Lomotil), and bismuth subsalicylate (sample brand names: Pepto-Bismol, Kaopectate). But they should not be taken as initial treatment as they can interfere with the natural mechanism of purging out harmful bacteria from the system. These are especially avoided if you have a fever or blood in the stool. Loperamide taken excessively can also lead to heart problems in some people. Discuss its use with health care professionals. 

If severe cases are left untreated, they can lead to a neurological disorder, severe dehydration, kidney disease, and even death.

Discuss your Symptoms with Our Doctor Now and Get Treated

Is Food Poisoning Contagious?

As explained earlier it is a food-borne disease, so by definition, it can not be transferred from one person to another person. Though outbreaks can occur in groups of people eating the same contaminated food. In short food poisoning is not contagious but rather preventable by maintaining good food hygiene.

There are 4 Cs to the prevention of Food poisoning:

1. Cleaning

  • The first step is cleanliness at all levels, From your hands to the kitchen to food.

2. Cooking

  • Cooking your food well is key to avoiding most bacteria, especially raw meat. The food should be steaming hot in the middle. Avoid raw meat. When reheating, food should be steaming hot all the way through. Avoid reheating more than once.

3. Chilling

  • Certain foods need to be properly refrigerated to avoid harmful bacteria from multiplying.

4. Cross Contamination

  • This happens when a certain contaminated food drips or comes in contact with other food. You should be particularly careful when handling raw meat. 

Is Stomach Flu Contagious?

Comparatively Stomach flu is contagious and requires prevention of spread. Outbreak environments include long-term care facilities (nursing homes in particular), restaurants, hospitals, schools, daycare centers, vacation destinations (including cruise ships), and military bases. Persons at particular risk are younger individuals, older adults, those who are institutionalized, and those who are immunosuppressed.

Prevention of stomach flu

  • It is advised to avoid sharing utensils, washing hands regularly and often, and avoid interactions within 48 hours of symptoms
  • Wash contaminated bedding or clothing in hot water separately
  • Avoid contact directly with vomitus or feces
  • Practice food Hygiene, Eat well-cooked food, and do not use food past expiry dates
  • Cook meat well, avoid it raw
  • Rinse fruits and vegetables well before consumption
  • Use pasteurized dairy products 
  • Drink bottled water while traveling 
  • Children can also get vaccinated against Rotavirus by following the standard vaccination schedule. Not all children can receive this vaccination thus you need to discuss it with a pediatrician before the administration

Severe Complications of Food Poisoning and Stomach Bug


Dehydration is a common complication of gastroenteritis. This occurs when your body loses fluids and electrolytes due to excessive vomiting and diarrhea.

Being dehydrated can be dangerous for young children, older people, and those who have a weakened immune system.

In case of severe dehydration, you might need to go to the hospital to get intravenous fluids.

Dehydration may result in serious problems, such as:

  • Heat Injury: Lack of fluids while you’re physically active, can lead to a life-threatening heatstroke.
  • Urinary and Kidney Issues: A prolonged or repeated dehydration episode can trigger kidney stones and urinary tract infections or lead to kidney failure.
  • Seizures: You could develop seizures when your electrolytes are not within the normal range.  
  • Hypovolemic Shock: This life-threatening condition occurs when low blood volume causes a decrease in blood pressure and consequently reduces the amount of oxygen in your body. 

Health problems during pregnancy

Almost one-third of pregnant women can have gastroenteritis during their pregnancy. 

Primarily pregnant women will recover from the sickness without any problems, but occasionally, it can lead to complications.

Severe dehydration from the illness can cause preterm labor. It has also been linked to miscarriages, low birth weight, and stillbirth. 

Irritable bowel syndrome

Another possible complication of gastroenteritis is post-infectious irritable bowel syndrome (IBS).

The presenting symptoms include diarrhea, nausea, stomach cramps, or constipation. Symptoms can last months or even years but eventually settle down.

Reactive Arthritis

An episode of gastroenteritis can lead to reactive arthritis. This is a type of a painful form of inflammatory arthritis. Reactive arthritis occurs in reaction to an infection caused by bacteria, including salmonella, campylobacter, yersinia, shigella, E. coli, vibrio, etc.

Reactive arthritis causes painful, red, and swollen joints, significantly affecting the knees, feet and ankles. Moreover, some people experience swelling of the membrane lining the eyes known as conjunctivitis or inflammation of the urinary tract. 

Recovery time varies from person to person. Some people get better after their first episode of symptoms. After that, symptoms can last from 3 to 12 months. For a certain percentage, symptoms recur or become chronic. 

What can be mistaken for food poisoning?

Hepatitis A: symptoms can be mistaken for food poisoning. These include fevers, joint aches, nausea, vomiting, and abdominal pain. Although children may have no symptoms at all.

Irritable Bowel Syndrome (IBS): When it comes to IBS, the symptoms are similar enough to food poisoning and stomach bugs so you can mistake them for each other. Although, IBS is a chronic condition and not a temporary sickness. Symptoms include abdominal pain or cramping, diarrhea or constipation, and excess gas and mucus in stool.

What Steps Should I Take After Food Poisoning?

  • You are advised to start bland foods, an easily digestible, low-fat diet
  • Stop eating if nausea returns
  • A gradual return to a normal diet is recommended
  • Drink plenty of fluids

When to See a Doctor?

See your doctor if you have the following red flag signs: 

  • More than six bowel movements in 24 hours  
  • Blood in vomit or stool 
  • High grade fever 101.3°F(38.5°C) persistent for more than a day 
  • Severe abdominal or belly pain 
  • If you are older than 70 years older 
  • If you feel dehydrated. Signs of dehydration include lots of diarrhea, feeling dizzy, irritable, muscle cramps, confusion, excessive thirst, low urine output, dry mouth, and tongue. 
  • Food poisoning while pregnant 

If you have any of the above-mentioned symptoms please visit a healthcare professional.

Worried About Your Symptoms of Food Poisoning , Consult Our Doctor for Treatment

FAQs About Food Poisoning By Your Doctors Online Team

How long does food poisoning last?

Most patients with mild to moderate disease improve in a few hours to a few days. . Severe disease may last a prolonged period of more than 10 to 14 days and may even require hospitalization and if not treated on time can even lead to complications like death.

How long is stomach flu contagious?

The virus can still be present in feces for 2 weeks even after the symptoms have disappeared, so be extra careful regarding washroom hygiene. Wash hygiene regularly.

Can a yeast infection cause stomach pain?

Yeast infections can lead to imbalances between good and bad bacteria which further leads to early food digestion and bloating. This bloating and gas lead to belly pain.

Can tooth infection cause stomach pain?

Tooth or gum infection can create an imbalance in mouth bacteria, these bacteria travel down to the stomach and cause inflammation there as well.

What drinks help food poisoning go away?

Food poisoning may cause symptoms like diarrhea and vomiting which lead to dehydration and electrolyte imbalances. Oral rehydration solutions (ORS), and sports drinks having both sugar and salt help replace lost fluid and electrolytes. 

Do vaccines help in Gastroenteritis?

Vaccines have been highly successful in reducing the global burden of rotavirus. Currently, they are recommended for infants older than 6 weeks but younger than 2 years; studies are underway to assess the safety and efficacy of starting vaccination in the newborn period.

What is the quickest way to get rid of a stomach bug?

To recover quickly, rest and staying well hydrated are recommended. If your tummy is still upset, taking frequent sips of water, sports drinks, broth or juice can help. It is essential to know that water alone may not be sufficient to keep you hydrated in severe cases of diarrhea, so electrolyte hydration is required.

How do you tell if a stomach bug is viral or bacterial?

Generally, viral gastroenteritis produces milder symptoms that last a few days and include nausea, vomiting, or diarrhea. Conversely, bacterial gastroenteritis is associated with more intense symptoms like severe abdominal pain and can last longer than a week without treatment. A fever and chills may also accompany these symptoms.

How fast does food poisoning happen?

Mostly, the symptoms of food poisoning appear soon after eating contaminated food. However, they may start at any point between a few hours and several weeks later.

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