Viral gastroenteritis
Alerts and Notices
Synopsis

Many viruses cause this syndrome, including noroviruses, rotaviruses, sapoviruses, adenoviruses, and astroviruses.
Adult patients typically present with acute onset (often within 24-48 hours of exposure) of diarrhea and vomiting. There is often associated nausea, fever, malaise, anorexia, and abdominal pain. The illness typically lasts about 2 days. Secondary attack rates can be high (especially if infection is due to the noroviruses).
Newborn infants may present with watery diarrhea and poor feeding. Fever and vomiting are less common. Some cases can be associated with electrolyte abnormalities. The illness may last up to 15 days. The severity of symptoms can vary and depend on the availability of adequate supportive care (some series report a high mortality). Although some viral pathogens have been associated with newborn nursery outbreaks, certain Escherichia coli strains are more commonly responsible.
Patients with AIDS or who are otherwise immunosuppressed may have a prolonged course associated with significant weight loss when infected with certain viral pathogens. One particular viral pathogen of importance in this population is cytomegalovirus. The differential diagnosis of diarrhea in immunosuppressed patients is quite broad, and it is helpful to involve an infectious diseases expert in the care of these patients.
Outbreaks of gastroenteritis are common in closed communities including schools, hospitals, cruise ships, and nursing homes as well as in restaurants or from catered meals.
For causes of bacterial gastroenteritis, see Gastroenteritis.
Codes
ICD10CM:A08.4 – Viral intestinal infection, unspecified
SNOMEDCT:
111843007 – Viral gastroenteritis
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
- Bacterial gastroenteritis – due to E. coli and other pathogens
- Gastroenteritis due to protozoan infection – Giardia, Cryptosporidium, Cystoisospora, Cyclospora
- Noninfectious causes of acute diarrhea – ingestions (eg, sorbitol or heavy metals), drug side effects (eg, as a side effect of mycophenolate mofetil), inflammatory bowel disease (eg, ulcerative colitis, Crohn), or thyrotoxicosis
- Noninfectious causes of chronic diarrhea – lactase insufficiency, celiac disease, bacterial overgrowth
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:11/30/2016
Last Updated:12/08/2022
Last Updated:12/08/2022


Overview
Viral gastroenteritis, or stomach flu, is the swelling of the stomach and intestines caused by a virus. People with viral gastroenteritis often experience diarrhea, stomach cramps, vomiting, and nausea. This virus is highly contagious and can be spread through contaminated food, water, or close person-to-person contact.Who’s At Risk
Gastroenteritis is common throughout the world. Those at higher risk for severe sickness include young children, older adults, and anyone who has a weak immune system. People who live in close contact with many others, such as in hospitals, schools, and nursing homes, are at a higher risk of being exposed to outbreaks of viral gastroenteritis.Signs & Symptoms
The most common symptoms of gastroenteritis include watery diarrhea, abdominal cramps, nausea, vomiting, and a slight fever. You may experience muscle aches or headaches. Symptoms usually appear 1-3 days after initial infection and can last for as long as 10 days.Self-Care Guidelines
After symptoms appear, limit solid food intake for a few hours to let your stomach settle. Because a lot of electrolytes and fluids are lost from diarrhea and vomiting, fluids with electrolytes (eg, Pedialyte, Gatorade) should be consumed in small amounts every 30-60 minutes. Bland food that is easy to digest such as bananas, plain yogurt, and vegetables should help with stomach discomfort.Use ibuprofen (Advil) cautiously as it can upset the stomach even more. Acetaminophen (Tylenol) should be used sparingly as it can cause liver toxicity, especially in children. Avoid over-the-counter anti-diarrheal medicine, as it may get in the way of your body's ability to fight the virus.
When to Seek Medical Care
Seek medical care if you are unable to keep down fluids because of nausea and vomiting. Also, if any of the following symptoms are present, contact a health care provider:- Blood in stool
- Dizziness / feeling faint
- No urine for at least 8 hours
- Confusion