What is acute gastroenteritis?

Q: What is acute gastroenteritis? How did my child get it?
 
A: Acute gastroenteritis (AGE) is infection of the gastrointestinal tract—usually presents as loose stools or diarrhea, vomiting with or without fever. It can be due to viral, bacterial or parasitic organisms—most commonly, though, it is caused by viruses.  Rotavirus is the most common cause of diarrhea and dehydration among children less than five years old. It is transmitted feco-orally (e.g. if somebody who just used the toilet and she didn't wash hands properly and prepared food, the bacteria/virus/parasite is transmitted to the food from her hands.)

For older children, bacteria and parasites may cause AGE because they are exposed to a wider environment (e.g. improperly cooked street food, parasites from outdoor activities like swimming in a lake, walking barefoot outdoors, etc.). Some natural disasters like floods can also lead to acute gastroenteritis due to contaminated food or water.

Treatment entails replacement of losses using ORS (oral rehydration solution), zinc supplementation to shorten the course of the illness and sometimes probiotics. For bacterial or parasitic gastroenteritis, specific treatment directed against the organism which caused the condition should be given.