Adults drinking milk powder diarrhea may be certain physiological factors, may also be caused by certain diseases, such as gastroenteritis, irritable bowel syndrome, intestinal flora imbalance, etc., such as persistent diarrhea should be timely consultation to identify the cause. 1. Physiological factors: If the water temperature of the milk powder is too cold, it can lead to gastric mucosa stimulation, peristalsis acceleration and diarrhea. 2. Pathologic factors: (1) Gastroenteritis: Gastroenteritis can be caused by expired milk powder, microbial infection or long-term consumption of too cold or too hot drinks or food, etc. It is usually manifested by gastrointestinal symptoms, such as diarrhea, epigastric pain, vomiting and so on, and in severe cases, dehydration and electrolyte disorders can also occur due to severe diarrhea and vomiting. (2) Irritable Bowel Syndrome (IBS): This is a common gastrointestinal dysfunction disorder, caused by intestinal infections, food intolerance, mental abnormality and other abnormalities of the gastrointestinal tract dynamics or sensory functions. Patients often experience persistent or intermittent episodes of abdominal discomfort, diarrhea, bloating and other symptoms. (3) Intestinal flora imbalance: the harmful bacteria in the intestinal tract multiply more, while the beneficial bacteria are less, which can lead to intestinal dysfunction and the symptoms of diarrhea after drinking milk powder. Adults drinking milk powder diarrhea, after excluding physiological factors, should consult a doctor in time, ask the doctor to clarify the cause of the disease, and if necessary, carry out appropriate treatment.