Nutritional therapy works to replace the fluids and nutrients that are lost from vomiting and diarrhea. It may also help prevent future bouts with some types of gastroenteritis.
Some bacteria occur naturally in the intestines and promote good health. These are called probiotics. The bacteria Lactobacillus, taken in supplement or food form, can build up the intestines' store of "good bacteria" and lessen the body's susceptibility to invading bacteria, such as Escherichia coli (which can cause traveler's diarrhea). Some practitioners of nutritional therapy recommend taking Lactobacillus acidophilus before going on an overseas trip.
Gastroenteritis may also be prevented by never eating protein-rich foods (such as meat, eggs, and cream) that have been undercooked or stored without refrigeration.
Dehydration can result when large amounts of water and electrolytes (including sodium, potassium, and glucose) are passed out of the body. Preventing it calls for drinking a lot of water mixed with small quantities of table salt and sugar. Fruit juices spiked with salt and sugar and nonfat vegetable broths can effectively replace lost fluids and electrolytes. Mineral supplements can also be helpful.
Until the symptoms have passed, spicy foods, oils, caffeine, animal fats including milk, and anything else that may irritate the stomach and intestines should be avoided. A diet of clear liquids and broths is best at first. When symptoms improve, graduate to a "BRAT" (bananas, rice, apples, and toast) diet.
The following can help replace fluids and electrolytes: Grate a carrot and cook in two cups of water; remove the carrot, salt the broth, and drink. Cases of severe dehydration require medical attention.