Food Poisoning vs. Stomach Bug (Stomach Flu) Quick Comparison
Food poisoning and stomach flu commonly cause stomach cramps.
- Food poisoning is a disease caused by eating or drinking food and/or water contaminated with viruses, bacteria, toxins, parasites and/or chemicals.
- Stomach flu (stomach bug, gastroenteritis) is a nonspecific term that can include food poisoning; however, the stomach flu usually is viral and for a few days (short-term).
- Food poisoning, depending upon the cause, usually is a more severe infection than the stomach flu. Some types of poisons can be lethal (for example, ingesting botulism toxin) while the stomach flu is rarely lethal (except in individuals severely dehydrated from nausea, vomiting, and/or diarrhea).
- Vomiting and diarrhea are common symptoms of the stomach flu and food poisoning. However, food poisoning symptoms usually are more severe, and often include other symptoms depending upon the cause (bloody diarrhea, nerve involvement as seen in botulism, fever and other symptoms).
- Both food poisoning and the stomach flu often occur in group settings that share food and drink and/or live in crowded conditions.
- Often, food poisoning can be traced back to a source of contaminated food, while stomach flu does not have to be related to specific food source. About one-half of stomach flu outbreaks have no specific cause.
- Both of these gut infections can be self-limiting, although the stomach flu is much more likely to be self – limiting than some food poisoning causes such as bacteria or parasites.
- The more severe symptoms of food poisoning and stomach flu often are treated by rehydration, both orally and occasionally by intravenous (IV) fluids.
- Most causes of the stomach flu are due to viruses so antibiotics are not useful. However, food poisoning from bacteria may require antibiotic therapy and other specialized therapy may be needed depending upon the parasites, chemicals, and/or toxins responsible for the disease.
- Treatment for nausea, vomiting, and/or dehydration is the same for both illnesses. Antidiarrheal medications may not be recommended for some causes of food poisoning.
- Food poisoning usually may last up to 10 days, depending upon the cause.
- The stomach flu usually lasts about 1 to 3 days. You can be contagious with the stomach flu for a few days up to about 2 weeks, depending on the infecting viral strain.
What Is Food Poisoning? What Is the Stomach Flu?
Food poisoning is an illness caused by eating or drinking food or water contaminated with viruses, bacteria, toxins, parasites, or chemicals. Typical symptoms of food poisoning are vomiting and diarrhea.
The stomach flu (gastroenteritis) is a general used term for various inflammatory problems in the digestive (gastrointestinal, GI) tract.
How Do You Get Food Poisoning vs. Stomach Flu?
Viruses are the most frequent cause of food poisoning in the U.S. The next highest causes are bacteria. Other causes include chemicals, parasites, toxins, and bacteria.
Foods most commonly associated with food poisoning include:
- Unpasteurized milk or other fluids
- Raw fruits and vegetables (usually unwashed
Gastroenteritis or the stomach flu can spread from person to person because of improper hand-washing following a bowel movement or handling a soiled diaper.
What Are the Signs and Symptoms of Food Poisoning vs. Stomach Flu?
Food Poisoning Symptoms and Signs
The most common signs and symptoms of food poisoning from most causes are:
- Abdominal cramps
However, symptoms infrequently can get worse. Other symptoms include:
Symptoms of food poisoning sometimes depend on which organ system the poison effects; for example, the neurological system may be altered by neurotoxins like pesticides and botulinum toxin.
When a group of individuals experiences similar symptoms after eating or drinking similar foods, food poisoning may be suspected.
Stomach Flu Symptoms and Signs
By definition, gastroenteritis affects both the stomach and the intestines, resulting in vomiting and diarrhea. Other symptoms and signs include:
- Low grade fever, usually less than 100 F (37.7 C)
- Nausea with or without vomiting
- Mild-to-moderate diarrhea (Dehydration also can intensify the symptoms of nausea and vomiting.)
- Crampy painful abdominal bloating (The cramps may come in cycles, increasing in severity until a loose bowel movement occurs and the pain re resolves somewhat leaving a dull ache.)
More serious signs and symptoms of stomach flu (gastroenteritis)
- Blood in vomit or stool (this is never normal and the affected individual should seek immediate medical care)
- Vomiting more than 48 hours
- Fever higher than 101 F (40 C)
- Swollen abdomen
- Increasingly severe abdominal pain
- Dehydration - weakness, lightheadedness, decreased urination, dry skin, dry mouth and lack of sweat and tears are characteristic symptoms of dehydration.
If symptoms continue or worsen, call a health-care professional. Diarrhea is one of the leading causes of infant sickness and death. Worldwide, diarrhea accounts for 3-5 million deaths yearly for all age groups. In general, most adults and children recover after they are appropriately rehydrated.
How Long Does Food Poisoning vs. Stomach Flu Last?
Depending on the cause of food poisoning, the duration of the majority of food poisoning usually ranges from a few hours after exposure to contaminated food or fluid to several days.
Gastroenteritis caused by viruses may last one to two days. However, some bacterial cases can continue for months.
Pancreatitis is inflammation of an organ in the abdomen called the pancreas.
When Should I See a Doctor If I Think I Have Food Poisoning or the Stomach Flu?
When to Call the Doctor for Food Poisoning
In the majority of individuals with mild to moderate symptoms of food poisoning (viral and bacterial), symptoms resolve in about 24 to 48 hours and no specific medical treatment is needed. However, if there are any signs of dehydration (decreased or no urination, dry mouth, increased thirst, dizziness and weakness), blood in the stools, fever, vomiting or diarrhea longer than 72 hours, medical care should be sought. If there is any reason to suspect that a more rare cause of food poisoning is causing symptoms described above, see a doctor.
When to Call the Doctor for Stomach Flu
Most often gastroenteritis is self-limiting, but it can cause significant problems with dehydration. Should that be a concern, contacting a primary care professional is reasonable.
Vomiting blood or having bloody or black bowel movements are not normal, and emergency care should be sought. Some medications such as iron or bismuth subsalicylate (Pepto-Bismol) can turn stool black in color.
Fever, increasing severity of abdominal pain, and persistent symptoms should not be ignored and seeking medical care should be considered.
What Is the Treatment for Food Poisoning vs. Stomach Flu?
Food Poisoning Treatment
The primary treatment for food poisoning is with fluids to avoid dehydration, especially in children and the elderly.
Some patients may benefit from medication to reduce nausea and vomiting. The use of medications like loperamide (Imodium) to treat diarrhea is often not advised as it may prolong symptoms or cause additional problems. Patients are advised to check with their doctor before using the medication. Antibiotics are not used to treat viral and most bacterial causes of food poisoning, but may be used in certain circumstances.
Severe bacterial infections and pregnant women with listeriosis will get antibiotics; some other pathogens such as certain parasites may be treated with antiparasitic medications. Other relatively rare causes of food poisoning may require special medications.
Home care for mild to moderate bacterial and viral food poisoning is mainly preventing dehydration. Fluid replacement by mouth using a combination of water and electrolyte solutions like Gatorade or Pedialyte is usually enough to avoid dehydration as long is enough is taken to replace the amount lost through diarrhea. A doctor or a specialist should treat infrequent or rare causes of food poisoning; moreover, this should be done in severe viral and bacterial food poisonings.
Stomach Flu Treatment
Antibiotics are not used to treat virus infections. Moreover, antibiotics usually are not prescribed until a bacteria or parasite has been identified as the cause of the infection. Antibiotics may be given for certain bacteria, specifically Campylobacter, Shigella, and Vibrio cholerae, if properly identified through laboratory tests. Otherwise, using any antibiotic or the wrong antibiotic can worsen some infections or make them last longer.
Some infections, such as Salmonella, are not treated with antibiotics. With supportive care comprising of fluids and rest, the body is able to fight off and rid itself of the infection without antibiotics.
For adults, the doctor may prescribe medications to stop the vomiting (antiemetics) such as:
Sometimes these medications are prescribed as a suppository.
Zofran is an effective anti-nausea medication used for infants and children.
Antidiarrheal medications are not usually recommended if the infection is associated with a toxin that causes the diarrhea. The most common antidiarrheal agents for people older than 3 years of age include over-the-counter (OTC) medications such as:
Reviewed on 1/17/2020
Gamarra, RM, MD. Food Poisoning Treatment & Management. Medscape. Updated: Jun 26, 2015.