Gastroenteritis is an inflammation of the stomach and intestines that can cause watery diarrhea, nausea and vomiting. Gastroenteritis is often called the "stomach flu." Common causes are:

• Viruses.
• Food or water contaminated by bacteria or parasites.
• Side effect from medicines.

• Nausea and vomiting.
• Diarrhea.
• Belly cramps.
• Low-grade fever (sometimes).

Adult

• Sip liquids. Sip a sports drink or water to prevent dehydration. Drinking fluids too quickly can make nausea and vomiting worse. Take small sips often over a couple of hours, instead of drinking a large amount at once.
• Take note of urination. You should be urinating at regular intervals, and your urine should be light and clear. Infrequent passage of dark urine is a sign of dehydration. Dizziness and lightheadedness also are symptoms of dehydration. If any of these symptoms occur and you can't drink enough fluids, seek medical attention.
• Ease back into eating. Try to eat small amounts of food frequently if you experience nausea. Otherwise, slowly begin to eat bland, easy-to-digest foods, such as soda crackers, toast, gelatin, bananas, applesauce, rice and chicken. Stop eating if your nausea returns. Avoid milk and dairy products, caffeine, alcohol, nicotine, and fatty or highly seasoned foods for a few days.
• Get plenty of rest. The illness and dehydration can make you weak and tired.

Child

• Encourage your child to rest.
• Offer fluids. When your child's vomiting stops, begin to offer small amounts of an oral rehydration solution (Ceralyte, Enfalyte, Pedialyte). Don't use only water or only apple juice. Drinking fluids too quickly can worsen the nausea and vomiting, so try to give small frequent sips over a couple of hours, instead of drinking a large amount at once. Try using a water dropper of rehydration solution instead of a bottle or cup.
• Introduce bland foods. Gradually introduce bland, easy-to-digest foods, such as toast, rice, bananas and potatoes. Avoid giving your child full-fat dairy products, such as whole milk and ice cream, and sugary foods, such as sodas and candy. These can make diarrhea worse.
• Breastfeed or bottle-feed. If you're breastfeeding, let your baby nurse. If your baby is bottle-fed, offer a small amount of an oral rehydration solution or regular formula.

Adult

See medical help if:

• Vomiting lasts more than two days.
• Diarrhea lasts more than several days.
• Diarrhea turns bloody.
• Fever is more than 102 Fahrenheit (39 degrees Celsius) or higher.
• You get lightheaded or faint when you stand.
• Confusion develops.
• Stomach pain develops.

Child

See medical help if your child:

• Becomes unusually drowsy.
• Vomits frequently or vomits blood.
• Has bloody diarrhea.
• Shows signs of dehydration, such as dry mouth and skin, marked thirst, sunken eyes, or crying without tears. In an infant, be alert to the soft spot on the top of the head becoming sunken and to diapers that remain dry for more than three hours.
• Is an infant and has a fever.
• Is older than 3 months of age and has a fever of 102 Fahrenheit (39 degrees Celsius) or more.