Stomach Flu: Symptoms, Causes, Risks, Complications, Diagnosis, Treatment and Prevention

A men who's holding his stomach because he suffer from stomach flu


Sudden vomiting, stomach pain, and loose bowel movement can be symptoms of stomach flu or a disease often called gastroenteritis. A virus or even bacteria can enter the body through contaminated foods, they can cause flu-like symptoms except for a runny nose and sore throats but fever and body weakness is apparent and can days.

The stomach flu can affect all age groups from a child to adults, up today there is no direct treatment for gastroenteritis, fluids, and proper hygiene is advisable when the flu infects you or when you know that there is an occurrence of stomach flu near you.


Although gastroenteritis has a flu-like symptoms, runny nose, sore throat and other respiratory problems are not seen during an episode of stomach flu. Most adults who suffer from gastroenteritis have similar symptoms that can have serious effects that can affect their lives like performing simple activities of daily living or even report to work. The symptoms include:

Loose bowel movement

The normal movement of the intestines is interrupted, because of the invasion of the virus or bacteria in the digestive system. The intestines will increase its peristaltic movement to remove the bacteria or virus in the system casing watery stools.


Aside from having a loose bowel movement, there will also be episodes of vomiting to eliminate the contents of the stomach. Sometimes it is accompanied by nausea.


As part of the body’s defense mechanism, there will be an increase in temperature to kill the virus or bacteria.

Abdominal cramps

The abdominal muscles will also be involved in the peristaltic movement, it will continuously contract during the flu.


There are viruses, bacteria, and microorganisms that can invade the normal flora of the intestines. Stomach flu that is caused by a virus have symptoms like diarrhea and abdominal cramps that can last up to 2 to 3 days and sometimes fever accompanies it.

It can be acquired by eating contaminated foods with the virus or bacteria. It can also be transferred from person to person who has been infected by, using their things like utensils. There many types of viruses that can cause stomach flu-like:


This type of virus is commonly seen in infants, the hand to mouth mechanism of toddlers can add to the factors on how they can acquire this stomach flu. The rotavirus affects toddlers greatly and young children symptoms may last for days and can have complications. In adults, the symptoms may not appear but still can be contagious to other people.


This type of virus affects both the children and adults. This can be acquired through foods that are contaminated and even water or it can be through direct contact with those people who have the virus. It can spread to other persons who live close to you and it is most common in small spaces that have no proper ventilation.

4Risk Factors

Stomach flu can is a widespread disease that can be passed around by direct contact or by consuming contaminated foods. Some people have experienced gastroenteritis or stomach flu once in their life, it is not confined to one age group but all can be affected by it.
Here are factors that can have the flu:


Children and the elderly are the once that are at risk of having severe symptoms like diarrhea accompanied by vomiting. At school age, the children can have this infection immediately after exposure because of their immune system is still developing and are unable to fight the virus effectively.

In elderly patients, their immune system is weakened as time pass, common cases of the stomach flu occur in nursing homes because of the closed environment that they live in, they can pass the virus easily through direct contact.

Decreases immune system

Those people whose immune system is compromised or weakened may easily be affected by the virus. People who are receiving chemotherapy or those who have AIDS or HIV have a high risk of getting infected by the virus or bacteria.

Crowded places

A high chance of acquiring the virus or the bacteria is by staying or going to populated areas like the park, malls and even in the church. Schools, dormitory and closed confined places can be a place the virus or bacteria can thrive and can be easily transmitted by direct contact.


The constant passing of watery stools and frequent vomiting can lead to dehydration if the symptoms are not managed properly. Dehydration is most likely to happen to infants and elderly patients as their immune system cannot handle the virus or bacteria well. There are ways to determine if the patient is dehydrated by looking this symptom on the patient:

  • A headache accompanied by dizziness
  • Dry mouth
  • Sunken eyes are noticeable
  • A very little output of urine
  • Easily tired and is weak
  • Irritable at times
  • In severe cases, they can lose consciousness and have a tachycardic episode.

Other complications may occur after the infection like:

Lactose intolerance

After having gastroenteritis, the lining of the stomach and intestines may have been damaged. The lack of coating in the digestive system can cause problems like inability to digest lactase that is commonly found on milk and dairy products.

Irritable bowel syndrome

The person who has encountered stomach flu several times can have irritable bowel syndrome.

Inability to absorb medicines

Due to the trauma caused by the infection in the intestines, there will be a decrease in the absorption of the medicines.

The infection may spread to the other parts of the body like the joints, if this happens it is most likely caused by a salmonella virus. Although this is not a common complication, other diseases may be triggered like arthritis or inflammation of other body parts


The symptoms of stomach flu are apparent and can be immediately determined that the person has the stomach flu. People who have this does not immediately go to the doctor, they prefer to stay at the house until the flu goes away in a couple of days, but when the symptoms persist, they can go and have a consultation.

The doctor will then do a physical assessment and will ask the complete history of the patient like:

  • What was the last food you ate?
  • When did you start feeling the pain?
  • Did you recently travel?
  • Have you taken any medicines?

The doctor may also order to do a stool exam for him to determine if the cause of the stomach pain is from a parasitic infection or a bacteria.


There is no known medicine to treat the stomach flu or gastroenteritis directly, but there are some home remedies to decrease the symptoms felt by the patient like:

  • Keep yourself dehydrated at all times to prevent fluid imbalance. Remember, every passing of stool or every time you vomit, replace the fluid that you lost to maintain the fluid balance in the body. Drinking about 200 ml to 300 ml of water every after an episode of diarrhea can prevent dehydration.
  • Have a light meal or the BRAT diet.
    • Bananas have potassium that can help replace the potassium that is lost during vomiting.
    • Rice is a carbohydrate that can replenish your energy when digested.
    • Applesauce is also a carbohydrate and can be easily digested to avoid agitating the intestines when digesting.
    • Toast is also easily digested.
  • Avoid drinking caffeinated products and chocolate drinks, this drinks can make you stay up all night and giving you little rest. Alcoholic drinks, on the other hand, can act as a diuretic, this can contribute to further fluid loss on the body.
  • Avoid eating hard to digest foods that can aggravate the intestines while digesting dairy products, food rich in fibers, oily and spicy foods.
  • Take antipyretics as instructed and prescribed by the doctor when you have a fever.
  • Have an adequate rest to recuperate.


To prevent having the stomach flu we should take special precautions and follow this tips to reduce the incidence of acquiring it.

  • Proper hand hygiene can reduce the risk of having the virus or bacteria by direct contact with other persons.
  • Make sure to eat clean foods and avoid eating street foods.
  • Clean your surroundings, clean and disinfect the furniture and things that are usually is constantly in contact with
  • Use your towel, toothbrush, and utensils to avoid contamination.
  • Avoid crowded places to minimize exposure to pathogens that may cause illnesses
  • Keep distance to someone who has the stomach flu.
  • When traveling, avoid putting ice cubes in your drinks, there might be a possibility that the water used to make the ice is contaminated.
    • Drink from a bottled water and only eat at a clean restaurant to prevent foodborne illnesses
    • Avoid undercooked food or even raw foods
  • Get your child a vaccine for gastroenteritis, some vaccines are given during the first year of life of the infant that can be used to prevent gastroenteritis.