When caring for a client with diarrhea, which aspect should the nurse closely monitor?

Monitoring fluid and electrolyte balance in a client with diarrhea is crucial because diarrhea leads to significant fluid loss and can disturb the body's electrolyte levels. As the intestines expel excess water and electrolytes, patients can quickly become dehydrated, risking serious complications like electrolyte imbalances, which can affect heart and muscle function, among other physiological processes.

In diarrhea, the body may lose not only water but also important electrolytes such as sodium, potassium, and chloride. An imbalance can lead to health issues like hypokalemia (low potassium) or hyponatremia (low sodium), both of which can have serious consequences. Therefore, assessing and managing fluid and electrolyte levels helps in preventing complications and ensuring the patient's recovery.

While factors such as skin condition, food intake, and fluid intake and output are also important to monitor, they are secondary to the immediate need to stabilize fluid and electrolyte levels to maintain overall homeostasis in the body.