Introduction:Diarrhea is a common pediatric condition and can be classified according to its duration: acute diarrhea, which lasts less than 2 weeks; chronic diarrhea, which lasts more than 2 months; and prolonged diarrhea, which lasts between the above two. Both acute diarrhea and chronic diarrhea can lead to a variety of complications if not treated properly, and should therefore be taken seriously. Pediatric diarrhea often causes the following complications: 1. dehydration and electrolyte disorders The body not only fails to effectively absorb water and electrolytes from food during diarrhea, but also loses them further in the form of intestinal fluid. Therefore, if water and electrolytes are not replenished effectively in time when diarrhea occurs, dehydration and electrolyte disorders of different degrees will occur. Among them, electrolyte disorders include low sodium, low potassium, low calcium and low magnesium, they are not only detrimental to the recovery of the disease, but also bring unnecessary pain to the child, for example, low potassium can cause stubborn bloating, low calcium can cause hand and foot twitching or convulsions. 2, viral myocarditis It occurs after diarrhea caused by enterovirus infection, diarrhea makes the child’s resistance further decline, the virus can invade the heart and cause viral myocarditis. Children with this disease may experience chest tightness, chest pain, palpitations, dizziness, and weakness. In severe cases, heart failure, cardiogenic shock, and even life-threatening cardiac arrhythmias may result. 3, intussusception One of the common acute abdominal diseases in children, mostly seen in infants aged 4 to 10 months. As the age increases, the incidence decreases. The vast majority of infants with intussusception are primary, and only 2% to 8% of cases are secondary. As a result of the loss of normal rhythm of intestinal peristalsis, persistent local spasm of the intestinal loop muscle occurs and the proximal intestine peristalsis is violent, thus pushing the spastic intestinal segment into the distal intestinal lumen. Diarrhea and its accompanying viral infection is the main cause of intussusception, should be alert. 4, malnutrition mostly occurs after prolonged diarrhea or chronic diarrhea. Malnutrition will make the child’s resistance further reduced, easy to secondary various infections, such as thrush, bronchopneumonia, tuberculosis, otitis media, urinary tract infections, etc., and diarrhea delayed will also aggravate malnutrition, resulting in a vicious circle.