Diarrhea after drinking beer may be related to chronic gastroenteritis, drinking too much alcohol, temperature stimulation and other reasons. 1. Chronic gastroenteritis: beer enters the gastrointestinal tract and produces gas, which can increase the burden on the gastrointestinal tract. If the patient himself suffers from chronic gastroenteritis, drinking beer will aggravate the condition, leading to abdominal pain, diarrhea and other conditions. 2. Drinking too much alcohol: beer contains alcohol, which can stimulate the gastrointestinal mucosa, leading to intestinal mucosal congestion, edema, and diarrhea can occur after drinking beer. 3. Temperature stimulation: If drinking beer is too cold, it can cause intestinal spasms, resulting in diarrhea. It is recommended that people who have diarrhea after drinking beer go to the hospital in time, clarify the cause of the disease, and standardize the treatment under the guidance of the doctor.