hi,thanks for query.Gastritis
is a general term,means inflammation of the wall of G.I. tract.Duodenal ulcer
means ulcer at due to this in duodenum
.The medicines and care required are more or less same.You need to be careful in both the cases and along with drugs you need to plan your diet carefully.Ulcer should heal within about 6-8 weeks with treatment.
wishing you good health.