What if i only drink water, why is my urine still dark yellow?

Depends on cause of: You had gastric ulcer in past, what was the cause of the ulcer.Most ulcers are caused by an infection with h pylori.And if it is treated suscessfully it is cured. Other causes are from prolonged use of non steroidal anti inflammatory drugs. Alcohol and tobacco use cancer of stomach untreated hpylori can cause recurrent ulcer others can recur if continuing use of alcohol, tobaco&nsaids.