In many cases of diarrhea, replacing lost fluid and salts is the only treatment needed, and is usually by oral rehydration therapy – or, in severe cases, intravenously.
WHO recommends that children with diarrhea continue to eat as sufficient nutrients are usually still absorbed to support continued growth and weight gain, and that continuing to eat also speeds up recovery of normal intestinal functioning.
CDC recommends that children and adults with cholera also continue to eat.
There is no evidence that early refeeding in children can cause an increase in inappropriate use of intravenous fluid, episodes of vomiting, and risk of having persistent diarrhea.
Medications such as loperamide (Imodium) and bismuth subsalicylate may be beneficial; however they may be contraindicated in certain situations.
Oral rehydration solution (ORS) (a slightly sweetened and salty water) can be used to prevent dehydration.
Standard home solutions such as salted rice water, salted yogurt drinks, vegetable and chicken soups with salt, water in which cereal has been cooked, unsalted soup, green coconut water, weak tea (unsweetened), and unsweetened fresh fruit juices can have from half a teaspoon to full teaspoon of salt added per liter.
Water can also be one of several fluids given.
Commercial solutions such as Pedialyte, and relief agencies such as UNICEF widely distribute packets of salts and sugar.
A WHO publication for physicians recommends a homemade oral rehydration solution consisting of one liter water with one teaspoon salt (3 grams) and two tablespoons sugar (18 grams).
Rehydration Project recommends adding the same amount of sugar but only one-half a teaspoon of salt, stating that this more dilute approach is less risky with very little loss of effectiveness.
Drinks with too much sugar or salt can make dehydration worse.
Appropriate amounts of supplemental zinc and potassium should be added.
Beginning preventing dehydration as early as possible.
Vomiting often occurs during the first hour or two of treatment with ORS, but seldom prevents successful rehydration.
Drinks high in simple sugars, such as soft drinks and fruit juices, are not recommended in children under five as they may increase dehydration.
A too rich solution in the gut draws water from the rest of the body, just as if the person were to drink sea water.
Plain water may be used if more specific and effective ORT preparations are unavailable or are not palatable.
Additionally, a mix of both plain water and drinks perhaps too rich in sugar and salt can alternatively be given to the same person, with the goal of providing a medium amount of sodium overall.
It is recommended that a child with diarrhea continue to be fed.
Continued feeding speeds the recovery of normal intestinal function.
Children whose food is restricted have diarrhea of longer duration and recover intestinal function more slowly.
Breastfeeding should always be continued.
In young children who are not breast-fed and live in the developed world, a lactose-free diet may be useful to speed recovery.
Eating food containing soluble fiber may help, but insoluble fiber might make it worse.
Antidiarrheal agents can be classified into four different groups: antimotility, antisecretory, adsorbent, and anti-infectious.
While antibiotics are beneficial in certain types of acute diarrhea, they are usually not used except in specific situations.
Antibiotics may increase the risk of hemolytic uremic syndrome in people infected with Escherichia coli O157:H7.
In resource-poor countries, treatment with antibiotics may be beneficial.
Some bacteria are developing antibiotic resistance, particularly Shigella.
Antibiotics can also cause diarrhea, and antibiotic-associated diarrhea is the most common adverse effect of treatment with general antibiotics.
While bismuth compounds (Pepto-Bismol) decrease the number of bowel movements in those with travelers’ diarrhea, they do not decrease the length of illness.
Anti-motility agents like loperamide are also effective at reducing the number of stools but not the duration of disease.
These agents should be used only if bloody diarrhea is not present.
Diosmectite, a natural aluminomagnesium silicate clay, is effective in alleviating symptoms of acute diarrhea in children.
Diosmectite has some effects in chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea.
Another absorbent agent used for the treatment of mild diarrhea is kaopectate.
Racecadotril an antisecretory medication may be used to treat diarrhea in children and adults, with better tolerability than loperamide, as it causes less constipation and flatulence.
It has little benefit in improving acute diarrhea in children.
Bile acid sequestrants such as cholestyramine can be effective in chronic diarrhea due to bile acid malabsorption.
Therapeutic trials of these drugs are indicated in chronic diarrhea if bile acid malabsorption cannot be diagnosed.
Zinc supplementation may benefit children over six months old with diarrhea in areas with high rates of malnourishment or zinc deficiency.
Probiotics make little or no difference to people who have diarrhea lasting 2 days or longer and that there is no proof that they reduce its duration.
For those with lactose intolerance, taking digestive enzymes containing lactase when consuming dairy products often improves symptoms.