Gastroenteritis is the term used to describe inflammation of the gastrointestinal tract. It is usually considered to be infective in origin when the term is used, however it can describe non-infective causes too. 

Importantly, subtle differences in the length of time between ingestion of food and development of symptoms can often reveal the causative agent; 

as a general rule: 

• bacterial toxins = hours

• viruses = days

• bacteria = weeks

• parasites = months.