Especially eHealthy. lucas643,, The lining of the stomach can heal within a couple of weeks, in cases where the gastritis was due to a discrete problem such as taking high doses of NSAIDs, and the inciting etiology was stopped.ikewise, if the problem was from stress, incorrect diet, medical problem, etc, then the underlying problem has to be corrected, before the stomach lining can get better. Gastritis is rarely a short term problem. It took some time developing, it is going to take some time to get over.