Diarrhea can manifest itself in two ways: first, as dehydration and second, as a change in mental status. The most common manifestations of dehydration are dry skin, sunken eyes and reduced urine output, or nausea, vomiting and poor digestion. Mental status is often generalized weakness, lack of energy, panic and chest tightness, or drowsiness. When diarrhea is present, most of the symptoms are water-electrolyte disturbance and dehydration. Therefore, for persistent or severe diarrhea, blood ion analysis should be done to clarify the electrolyte disorder. If there is low potassium, low sodium or elevated blood levels, hydration and electrolyte balance should be actively replenished, and anti-inflammatory drugs should be given. It is also necessary to improve the routine stool examination and assist in the diagnosis and treatment.