Diarrhea Hydration and Nutrition (ORS and BRAT Diet)

The main complication of diarrhea is dehydration. It is one of the leading causes of death globally as a result of diarrheal illnesses like gastroenteritis. Hydration and nutrition are crucial for the management of diarrhea and possible prevention of complications. Hydration restores essential fluid and electrolyte that is lost in the diarrheal stool. Nutrition provides much needed nutrients to maintain health and avoid deficiencies that can occur with nutrient loss in watery stool that is typical of diarrhea.

Should you stop eating and drinking with diarrhea?

There are misconceptions that all food should be avoided until the diarrhea resolves. Solid food should only be avoided if there is vomiting but hydration should continue. Oral rehydration therapy (ORT) using oral rehydration solutions (ORS) is necessary. Solid foods can be commenced thereafter and the BRAT diet may be an option for the initial solid meals. A better option is to commence bland but balanced meals of solid foods once it is tolerated.

Rehydration is necessary to prevent dehydration which is a result of fluid and electrolyte loss from vomiting and diarrhea. Once vomiting ceases, a person may not be able to tolerate full meals immediately. The BRAT diet comprises the first foods that can be introduced. Thereafter, bland but balanced meals can be commenced. It is important to note that the BRAT diet is no longer recommended by health authorities as it has insufficient nutrition.

Therefore the BRAT diet can be avoided altogether and bland balanced meals should be commenced as soon as possible. When oral hydration (drinking fluids) and nutrition of solid foods is not possible then hospitalization and IV administration of fluids, electrolytes and nutrition may then be necessary.


Clean drinking water is necessary for rehydration. Water alone is suitable but water with electrolytes is preferable.This mixture of water and electrolytes is known as an oral rehydration solution (ORS). It helps to restore both the lost water in diarrheal stool as well as the lost electrolytes that accompanies this water.

Apart from commercial and homemade ORS, sometimes other beverages are used for rehydration, such as soft drinks and fruit juice. However, this may not always be suitable. In the event that an oral rehydration solution is not tolerable or the diarrhea is very severe, intravenous (IV) administration of fluids and electrolytes is essential.

Read more on ways to treat dehydration.

Types of Oral Rehydration Solutions (ORS)

The ideal ORS (oral rehydration solution) 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. It should be used short term if no oral rehydration solution is accessible.
  • Fruit juice (like apple, orange) have trace amounts of sodium (inadequate), sufficient potassium and no chloride.
  • Breast milk and bottle feed should be continued and NOT stopped. 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.

It is important to note that alcohol and caffeinated beverages like coffee should be avoided. Both alcohol and caffeine have a diuretic effect. This means that it hastens fluid loss primarily through urine. At a time of dehydration or impending dehydration, alcohol and caffeine can worsen the situation and should therefore be avoided.

Quantity of Oral Rehydration Solution (ORS)

  • The normal fluid consumption for an adult in a day should be at least 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 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.

Read more on signs of dehydration.


The BRAT diet is convenient for restoring a diet of solid foods. It stands for bananas, rice, apples and toast. However, this is only suitable for short term after vomiting subsides. A person must restore a full solid diet of bland meals that are balanced for maximum nutrition. The BRAT diet can be skipped altogether if a person can tolerate a solid bland meal immediately.

Adhering only to the BRAT diet long term is unsuitable. There may be insufficient nutrients for health and well being. For this reason, some health authorities no longer recommend the BRAT diet. In the event of diarrhea without vomiting, the BRAT diet is not necessary. Bland solid foods should be consumed when diarrhea alone is present.

What is the BRAT diet?

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. It is important to remember that 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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