The biggest danger with gastroenteritis is that the vomiting and diarrhea will cause excessive water loss and the patient may dry out or dehydrate. Our body is 70 percent water which is necessary for blood flow and body functions. When the patient is urinating regularly, at least twice a day, then there is probably enough water in the body. To prevent dehydration it is best to give the patient a simple mixture of water, sugar and salt. In this way, the water is best taken in and retained.
Foods tend to make the irritation of the bowels worse and cause further water loss.
Fruit juices also loosen the stools and should be avoided. This is called the oral electrolyte solution and is used for Oral Rehydration Therapy or ORT . Commercially, this preparation is sold as Pedialyte or Infalyte. When the patient is vomiting often just start with 1 tablespoon of the solution every 20 minutes and increase gradually as tolerated. If the patient is on breast milk, then breast-feeding may be tried.