Reason of vomiting after drinking water?

Vomiting or regurg?: Big difference--if regurgitating foods as you describe (that promote gastroesophageal reflux), then you probably are describing gerd & diet modification (& acid reducer) is in order. If you are really vomiting as often as your question implies, then you have a bigger problem that warrants medical evaluation (checking for ulcers, gallbladder disease, pancreatitis, gastroparesis, obstruction, etc.).