Oral Rehydration Therapy and BRAT Diet (Diarrhea, Vomiting)

Rehydration is necessary to prevent dehydration due to the fluid and electrolyte loss from vomiting and diarrhea as well as offering some source of nutrition, although minimal.

The BRAT diet or diarrhea diet are the first foods that should be introduced to a person after a bout of diarrhea or vomiting.


Types of Oral Rehydration Solutions (ORS)

The ideal ORS should contain a minimum of 60 mmol of sodium (Na), 20 mmol of potassium (K) , 80 mmol of chloride (Cl) and provide at least 50kCal of energy per liter of water. Most commercial rehydration solutions provide slightly higher levels of these electrolytes and glucose which is adequate.

  • Soft drinks or sodas have insufficient quantities of sodium and potassium and most do not have chloride.
  • Fruit juice (like apple, orange) have trace amounts of sodium (inadequate), sufficient potassium and no chloride.
  • Breast milk and bottle feed should not be discontinued. Babies under 6 months of age should not be given oral rehydration solutions unless otherwise advised by a medical professional.
  • Home made ORS may be the only option in some situations but should not be used for more than a day. This usually consists of 8 teaspoons of sugar, 1/2 teaspoon of salt mixed per liter of boiled and cooled water. It lacks potassium and inappropriately prepared home made ORS may lead to other complications. Only use home made ORS if no other means of rehydration is available – example traveling to a desolate location.

Quantity of Oral Rehydration Solution (ORS)

  • The normal fluid consumption for an adult in a day is 1 to 2 liters. In a moderate case of diarrhea an adult may lose 500ml to 1 liter of fluid per day from watery stools and in severe cases (like cholera), this can exceed 10 liters within 24 hours.
  • Fluid replacement in a 24 hour period should therefore be the equivalent of the normal daily intake (1 to 2 liters) in addition to replacing the fluid loss from vomiting and diarrheal stool (500ml to 1 liter). This should be sipped in small quantities if the nausea is severe.
  • If a person vomits within 20 minutes of drinking an ORS, this quantity of ORS is probably lost and needs to be replaced.
  • Inadequate oral rehydration with signs of severe dehydration will require hospitalization and IV infusion.


These are the foods that should be consumed once the vomiting settles and the patient feels well enough to eat solids. Only small amounts should be consumed at a time and if well tolerated (after 1 hour with no vomiting), another portion can be eaten.

  • Bananas – mashed
  • Rice – plain, white, no seasoning
  • Apple – grated, no peel or applesauce is preferable if available.
  • Toast – no butter/margarine

Other foods/drinks that could be added to the above diet is tea (black) or yogurt. The use of yogurt should be monitored carefully as it can aggravate the diarrhea due to secondary lactose intolerance which is short term.

The BRAT diet is not suitable for long term nutrition as it lacks sufficient protein, fat and fiber. A normal but bland diet should be commenced as soon as possible.

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