Diarrhea describes the passage of loose or watery stools at least three times in a 24-hour period. It makes the second leading cause of child mortality. Diarrheal illness includes acute watery diarrhea, invasive (bloody) diarrhea, or chronic diarrhea (persistent ≥14 days).

The health care provider must classify the type of diarrheal illness at presentation, assess and correct fluid and electrolyte losses, administer appropriate nutrition, and manage associated co-morbid conditions. 

It is crucial to assess the degree of dehydration at presentation based on physical signs and symptoms. Fluid management can be carried out in two phases: replacement and maintenance. The replacement therapy aims to replenish deficits in water and electrolytes lost and is continued until all signs and symptoms of volume depletion are absent, and the patient has urinated. Whereas, Maintenance therapy counters ongoing losses of water and electrolytes; and is continued until all symptoms resolve.

For Managing Acute watery diarrhea, fluid and electrolytes are the key requisites. Broadly, the approach to rehydration in patients with severe malnutrition should be conservative because of the risk of fluid overload. Intravenous fluids should be reserved for patients with overt shock. 

All patients with severe malnutrition and diarrhea should receive empiric broad-spectrum antibiotics immediately and appropriate nutritional therapy.

Nutrition management in patients without malnutrition is crucial to encourage sufficient feeding both during and after the diarrheal illness episode to prevent the development of malnutrition and chronic enteropathy. 

Most children with acute watery diarrhea do not require Antibiotics; however, suspected cholera is an important exception in which antibiotic therapy is warranted.

Managing Invasive diarrhea requires the same approach to fluids, electrolytes, and nutrition as acute watery diarrhea. Additionally, it demands empiric antibiotic therapy with activity against Shigella species.

Acute diarrhea can be prevented among children in resource-limited settings with breastfeeding, safe food and water consumption, adherence to hygienic practices, and vaccination against rotavirus infection. 

Harris JB, Pietroni M. Approach to the child with acute diarrhea in resource-limited countries. UpToDate. 2022. https://www.uptodate.com/contents/approach-to-the-child-with-acute-diarrhea-in-resource-limited-countries#H1159942320.