Causes of bitter water when vomiting include dietary bitter food, gastroesophageal reflux, cholecystitis and so on. 1. Eating and drinking bitter food: If the patient eats bitter food, such as bitter melon, almonds, lotus seeds, etc., the bitter alkaloids will be separated after the food enters the stomach, and when the patient vomits, the solution in the stomach will be mixed with bitter alkaloids, which will be manifested as vomiting bitter water. 2. Gastroesophageal reflux: when the patient suffers from this disease, due to the complex composition of the solution in the stomach, gastric acid, bile, pancreatic fluid and other solutions refluxed into the stomach, which will stimulate the gastric mucosa and esophageal orifice mucosa, leading to vomiting, and vomiting bitter water. 3. Cholecystitis: bile in the gallbladder is a bitter liquid, when there is inflammation and degeneration of the gallbladder, bile will be secreted excessively, when the patient vomits, bile is mixed with it, and the taste of the vomited liquid will become bitter. When the patient vomits and vomits bitter water, it is recommended that the patient go to the hospital to have a relevant examination to clarify the cause of the disease and get treatment as soon as possible.