Diarrhea for three or four days is considered to be related to various diseases such as irritable bowel syndrome, acute enteritis, intestinal flora disorders, etc. Montelukast, ciprofloxacin, lactobacillin tablets can be used. 1. Irritable bowel syndrome: it is a kind of intestinal dysfunction disease with continuous or intermittent attack and lack of organic abnormality. The symptoms of diarrhea for three or four days may occur, which may be accompanied by clinical manifestations such as change in stool properties, loss of appetite, nausea, and abdominal distension. It is recommended to take montelukast to control the symptoms of diarrhea, scopolamine and other antispasmodic according to medical advice. 2. Acute enteritis: during the onset of acute enteritis, patients may have obvious diarrhea symptoms, and may be accompanied by loss of appetite, abdominal pain, vomiting and fever and other clinical manifestations. It is recommended to take ciprofloxacin tablets and other drugs according to the doctor’s instructions for targeted treatment. 3. Intestinal flora disorders: Intestinal flora disorders can be caused by the decrease in the number or activity of beneficial bacteria in the intestinal tract, which affects the digestion, decomposition and absorption of food and triggers mild diarrhea symptoms. During this period, patients may also experience loss of appetite, bloating, abdominal pain or constipation and other clinical manifestations. It is recommended to take lactobacillus tablets and other probiotic drugs as prescribed by the doctor to regulate. There are many types of primary causes of diarrhea for three to four days, and it is necessary to actively go to the hospital, according to the results of routine blood tests, fecal routines, abdominal ultrasound and other related tests to determine the cause of the disease, and then use medication under the guidance of the doctor.