Taking nexium for years but chronic gastritis wont go away. could it be a side effect of nexium itself?

Scope or not to scop: Nexium is not a cure; it's there only to reduce the problem of acidity. Your doctor should probably refer you to a gastroenterologist at this time to get an upper scope. Then again, that's my opinion. If you have an ulcer, nexium helps with healing, but won't cure the ulcer. I guess if you have chronic gastritis, is because you were scoped already?