How are symptoms different between gastritis and gastric/peptic ulcer?

They can overlap.: Some symptoms of gastritis and gastric ulcer can be the same - abdominal pain and discomfort. Some times an ulcer can cause more severe pain and if it is causing bleeding people will have black bowel movements or "melena " as a result. Sometimes an evaluation by a physician with lab work and possibly EGD (scope to look in stomach to visualize esophagus and stomach lining) is the only way to tell