Viral gastroenteritis (widely known as the “stomach flu” or “stomach bug”) is one of the most common and highly contagious digestive illnesses. Caused by viruses that spread through “person to person” contact or contaminated food and water, it triggers a range of uncomfortable gastrointestinal (GI) symptoms. While the infection typically resolves on its own, severe cases or complications can necessitate medical intervention. 

In this article, we will explore the symptoms and causes, discuss effective treatment and prevention strategies, and advise on when to seek care from a medical professional (including a gastroenterologist).

Symptoms And Complications

Viral gastroenteritis is an acute inflammation of the digestive tract, which includes the stomach and intestines. 

Most Common Symptoms Of Stomach Flu 

  • Abdominal pain or cramps
  • Diarrhea
  • Loss of appetite
  • Nausea and vomiting

Severe or prolonged cases may cause systemic symptoms, such as:

  • Fatigue
  • Fever and/or chills
  • Headache
  • Muscle aches
  • Swollen lymph nodes

Symptoms typically occur within 24 to 72 hours following exposure. Onset is often sudden with symptoms usually lasting for a few days. In severe cases, they may last longer (up to two weeks). Stomach flu is self-limiting for the majority of people. Complications can arise, particularly among vulnerable populations (infants, the elderly or the immunocompromised).

The most common complication is dehydration, resulting from the significant fluid and electrolyte loss with vomiting and diarrhea. The clinical signs of dehydration include extreme thirst, sunken eyes, decreased urination and lethargy. In severe cases, people can have a rapid heartbeat, low blood pressure and confusion. Dehydration requires prompt intervention because it can rapidly progress to a life-threatening state.

 

Causes And Risk Factors

Viral gastroenteritis is caused by viruses: the most common being noroviruses in adults and rotavirus in children. These highly contagious viruses are spread by:

  • Eating or drinking contaminated food or water.
  • Sharing utensils and other personal items with an infected person.
  • Person-to-person contact.
  • Touching a contaminated surface.

Although anyone can catch a stomach bug, it is more likely to affect populations that are more susceptible to infection. This includes young children, elderly people, people with chronic illnesses or people with weakened immune systems. Because the viruses are highly contagious, outbreaks commonly affect childcare centers, schools, dormitories and nursing homes.

Diagnosis

Diagnosis of gastroenteritis is typically made clinically based on the patient’s reported symptoms. Determining the specific cause (viral, bacterial or parasitic) requires laboratory analysis. Diagnostic testing is not standard practice for most cases. However, stool-sample analysis may be ordered by a physician when necessary to rule out bacterial or parasitic infection.

Treatment

Treatment for viral gastroenteritis involves staying at home to avoid spreading the virus to others and using self-care measures to ease the symptoms.

  • Stay hydrated with plenty of fluids and electrolytes.
  • Eat bland foods in small amounts to settle the stomach.
  • Get plenty of rest.
  • Avoid rich foods and alcohol.
  • Antidiarrheals may be helpful for adults, but they should not be used if you have bloody stool or fever. Do not give them to children unless directed by a doctor.

Most people recover within a few days, but they remain contagious for up to 48 hours once the symptoms pass. You should continue to stay at home for two days after the illness resolves.

Prevention

Viral gastroenteritis cannot always be prevented. You can reduce your risk by practicing proper hygiene and taking other preventive measures.

  • Washing your hands frequently and thoroughly is the best defense against stomach bugs. Use soap and water, and wash for at least 20 seconds. Ensure that you clean all parts of the hands, including under the fingernails. Wash your hands after using the bathroom, handling diapers, and before preparing or eating food.
  • Using hand sanitizer can reduce your risk of infection when washing your hands isn’t an option. It is not as effective as hand-washing, so don’t use this as your go-to method.
  • Practice safe food-handling. Ensure that kitchen surfaces and utensils are sanitized before use. Follow food-safety guidelines when preparing food.
  • Avoid sharing personal items, such as cups, utensils and towels.
  • Take precautions around infected people. Avoid contact with anyone who has gastroenteritis. In a household with an infected person, be sure to disinfect hard surfaces. Avoid touching dirty laundry, and use hot water to wash bedding and clothing.

When To See A Doctor

You should contact your healthcare provider if you have:

  • Signs of severe dehydration.
  • Lack of urination or vomiting that has lasted for two days.
  • Blood in your vomit or stool.
  • Severe abdominal pain.
  • No symptom improvement or a high fever after a few days.

For babies and children, seek medical advice if they have:

  • A fever of 102° F or higher.
  • Signs of dehydration, including a sunken spot on the top of the head (in babies), dry mouth or crying without tears.
  • Frequent vomiting.
  • Bloody stools.
  • Lack of urination.

Should I Call My Gastroenterologist For A Stomach Bug?

Generally, no. You should contact your primary care physician or an urgent care center for acute gastroenteritis. Gastroenterologists typically handle more complex or chronic digestive conditions. Your doctor may refer you to a gastroenterologist for further investigation if your symptoms are severe or prolonged.

The team at GastroIntestinal Specialists, A.M.C., treats multiple conditions and diseases of the gastrointestinal (GI) tract. Our board-certified physicians have more than 150 years of combined experience in providing quality care you can trust. To schedule an appointment, call (318) 631-9121 or visit gis.md.