Vomiting black water after drinking alcohol may be caused by taking iron-containing foods or drugs, stomach bleeding and other reasons. 1. Taking iron-containing foods or drugs: If you take iron-containing foods or drugs such as spinach, animal blood products, liver, ferrous sulfate, ferrous succinate, etc. before or during drinking, iron ions are oxidized to black in the gastrointestinal tract and may appear as a symptom of vomiting black water after drinking. 2. Gastric bleeding: when suffering from erosive gastritis, gastric ulcer and other gastric diseases, under the effect of alcohol stimulation of gastric mucosa, bleeding increases, hemoglobin in the iron is oxidized may also appear after drinking spit black water symptoms. If you have the symptom of vomiting black water after drinking, you need to go to the hospital for further examination of blood routine, stool routine, gastroscopy and other items to find the cause.