Try to Replace Fluids During a Bout of Gastroenteritis

When you're laid up with gastroenteritis, also known as stomach flu, you may wonder what you could eat that wouldn't make you feel worse. Actually, fluids are the best gastroenteritis diet.

Gastroenteritis is swelling and irritation — inflammation — of your stomach and your intestines, caused by a viral, bacterial or parasitic infection, according to the Cleveland Clinic. Inflammation of your stomach causes loss of appetite, nausea and vomiting, and intestinal inflammation can cause watery diarrhea.

Most people get gastroenteritis from a virus, sometimes called stomach flu, although it's not caused by the seasonal influenza virus, Cleveland Clinic notes. Norovirus is a common culprit.

"If you have a typical stomach bug, the main danger is dehydration from vomiting and diarrhea," says Julia Zumpano, RD, LD, a registered clinical dietitian in the nutrition therapy department at the Cleveland Clinic in Ohio. "Even though you may not have any appetite, you should try to replace fluids. If your symptoms last for more than two days, and you are unable to keep fluids down, you need to see your doctor."

The Cleveland Clinic explains that when you lose fluid through diarrhea and vomiting, you also lose important blood minerals, called electrolytes.

"You can replace water and electrolytes like sodium and potassium with a sports drink or an electrolyte-enhanced replacement drink," says Zumpano. "Other good replacement fluids include coconut water, chicken broth or bone broth."

​Read more:​ Healthy Electrolyte Drinks

Mayo Clinic suggests that you sip fluids slowly and frequently over a few hours, instead of drinking quickly, which may make nausea and vomiting worse. However, some fluids themselves can make nausea and vomiting worse. The National Institutes of Health (NIH) says to avoid drinks with caffeine, like coffee, tea and caffeinated soft drinks, and also avoid high-sugar drinks. Some people with gastroenteritis may have trouble digesting the protein in milk (lactose), so you should avoid milk because it may make diarrhea worse.

Try to drink enough fluid to keep your urine clear or pale yellow. If you can't keep fluids down, or vomiting and diarrhea last more than a few days, you need to watch out for dehydration. Cleveland Clinic says to call your doctor if you have these signs of dehydration:

• Extreme thirst
• Dark urine
• Dry skin and mouth
• Dizziness

According to the NIH, research shows that there's no gastroenteritis diet that will help treat this condition. However, you can start eating food as soon as you stop vomiting and your appetite comes back — you don't need to wait until your diarrhea is gone, NIH says.

Mayo Clinic, though, suggests that it's best to ease back into your diet by eating smaller, more frequent meals until you see how your stomach reacts.

"Everybody's digestive system reacts differently to foods, but most people will do better if they avoid foods that are fatty, spicy or hard to digest," advises Zumpano.

Mayo Clinic advises starting with easy-to-digest foods, such as:

• Soda crackers
• Toast
• Gelatin
• Bananas
• Applesauce
• Rice
• Chicken
  

Also, NIH warns that some people may not be able to tolerate lactose for a month or more after gastroenteritis, even if they were not lactose intolerant previously, so be careful reintroducing milk products. If they cause cramping and diarrhea, try waiting for a few weeks.

​Read more:​ Foods to Avoid If You Have Gastroenteritis

The treatment of gastroenteritis depends on its cause. For instance, medications may be needed to treat gastroenteritis caused by bacteria or parasites. Be sure to let your doctor know if you have fever or bloody diarrhea along with nausea and vomiting as these may be signs of bacterial or parasitic gastroenteritis. Viral gastroenteritis usually clears up on its own.

Also check in with your doctor, Mayo Clinic advises, if you have:

• Vomiting for more than two days
• Diarrhea for more than three to four days
• Bloody diarrhea
• A fever over 102 degrees Fahrenheit
• Severe belly pain
  
• Signs of dehydration