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An infection or irritation of the stomach and intestines, which may be caused by viruses or by bacteria or parasites from spoiled food or unclean water. Symptoms include diarrhea, nausea, vomiting, and abdominal cramping.

PubMed Health Glossary
(Source: NIH - National Institute of Diabetes and Digestive and Kidney Diseases)

About Viral Gastroenteritis

Viral gastroenteritis is inflammation of the lining of the stomach, small intestine, and large intestine. Several different viruses can cause viral gastroenteritis, which is highly contagious and extremely common. Viral gastroenteritis causes millions of cases of diarrhea each year.

Anyone can get viral gastroenteritis and most people recover without any complications, unless they become dehydrated.

What are the symptoms of viral gastroenteritis?

The main symptoms of viral gastroenteritis are

Other symptoms include

Symptoms usually appear within 12 to 48 hours after exposure to a gastroenteritis-causing virus and last for 1 to 3 days. Some viruses cause symptoms that last longer...Read more about Viral Gastroenteritis NIH - National Institute of Diabetes and Digestive and Kidney Diseases

What works? Research summarized

Evidence reviews

Enteral vs intravenous rehydration therapy for children with gastroenteritis: a meta-analysis of randomized controlled trials

OBJECTIVE: To review the relative efficacy and safety of enteral vs intravenous (IV) rehydration therapy in treating childhood gastroenteritis.

Meta-analysis shows limited evidence for using Lactobacillus acidophilus LB to treat acute gastroenteritis in children

A meta-analysis of four randomised controlled trials of varying methodological quality, involving 304 children aged 1-48 months, showed that Lactobacillus acidophilus LB (LB) reduced the duration of diarrhoea in hospitalised, but not outpatient, children compared with a placebo. The chance of a cure on day three was similar in both groups, but LB increased the chance of cure on day four.

Racecadotril for childhood gastroenteritis: an individual patient data meta-analysis

This individual patient data meta-analysis of nine trials found that racecadotril as an adjunct to oral rehydration solution had a clinically relevant effect in reducing diarrhoea (duration, stool output and number) in children with acute gastroenteritis. Despite some shortcomings regarding the available evidence and model uncertainty, this conclusion is likely to be reliable.

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Summaries for consumers

Children with dehydration due to gastroenteritis need to be rehydrated, and this review did not show any important differences between giving fluids orally or intravenously

Dehydration is when body water content is reduced causing dry skin, headaches, sunken eyes, dizziness, confusion, and sometimes death. Children with dehydration due to gastroenteritis need rehydrating either by liquids given by mouth or a tube through the nose, or intravenously. The review of 17 trials (some funded by drug companies) found that the trials were not of high quality; however the evidence suggested that there are no clinically important differences between giving fluids orally or intravenously. For every 25 children treated with fluids given orally, one child would fail and require intravenous rehydration. Further, the results for low osmolarity solutions, the currently recommended treatment by the World Health Organization, showed a lower failure rate for oral rehydration that was not significantly different from that of intravenous rehydration. Oral rehydration should be the first line of treatment in children with mild to moderate dehydration with intravenous therapy being used if the oral route fails. The evidence showed that there may be a higher risk of paralytic ileus with oral rehydration while intravenous therapy carries the risk of phlebitis (ie inflammation of the veins).

Anti‐sickness medication for vomiting in acute stomach upsets in children

Vomiting caused by acute gastroenteritis is very common in children and adolescents. Treatment of vomiting in children with acute gastroenteritis can be problematic and there is lack of agreement among clinicians on the indications for the use of antiemetics. There have also been concerns expressed about apparently unacceptable levels of side effects with some of the older generation of antiemetics. The small number of included trials provided evidence which appeared to favour the use of antiemetics over placebo to reduce the number of episodes of vomiting due to gastroenteritis in children. A single oral dose of ondansetron given to children with mild to moderate dehydration can control vomiting, avoid hospitalization and intravenous fluid administration which would otherwise be needed. There were no major side effects other than a few reports of increased frequency of diarrhea.

Tacrolimus for treatment of active treatment resistant ulcerative colitis

One study that tested the effectiveness of tacrolimus as therapy for treatment resistant ulcerative colitis was reviewed. Ulcerative colitis is a relapsing inflammatory disease restricted to the colon. Symptoms include bloody diarrhea, passage of pus and/or mucus and abdominal cramping during bowel movements. Tacrolimus is an immunosuppressant that may inhibit transcription of the interleukin 2 gene required for T cell activation thereby suppressing the inflammation associated with ulcerative colitis. The study compared two dosing regimens of tacrolimus (high serum concentration and low serum concentration) with placebo (inactive pill) and found that tacrolimus was effective for improving the symptoms of ulcerative colitis at two weeks. No benefit for induction of remission was noted. Patients in the high serum concentration group were significantly more likely than placebo patients to experience side effects related to treatment. Most of the side effects that occurred during the study were mild and included finger tremor, sleepiness, hot flush, headache, queasiness, stomach discomfort, hypomagnesemia and kidney problems. Two patients developed serious side effects during the study. One patient in the high serum concentration group developed serious viral gastroenteritis. A patient in the low serum concentration group developed Acinetobacter sepsis. Tacrolimus treatment was withdrawn in these patients and both patients recovered after medical therapy. Other side effects that have been associated with tacrolimus in other studies included liver problems, seizures, hypertension, diabetes mellitus, hyperkalemia, itching, insomnia, confusion, loss of appetite, hyperglycemia, weakness, depression, cramps, neuropathy, and infections. Tacrolimus may be effective for short‐term improvement in symptoms in patients with treatment resistant colitis. There are no data from controlled trials to allow conclusions with regard to long term safety and effectiveness. The use of tacrolimus needs to be weighed against the potential risk of serious side effects. More data from well designed and controlled studies are needed to determine the long‐term safety and effectiveness of tacrolimus.

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More about Gastroenteritis

Photo of an adult

Also called: Gastro, GE

See Also: Diarrhea

Other terms to know:
Norovirus, Viruses

Keep up with systematic reviews on Gastroenteritis:


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