My Husband Is A Relatively Healthy 91 Year Young World

My husband is a relatively healthy 91 year young world war two veteran who has back back now when he picks up the garbage to take it out plus hea takes medicine from the v.a. for blood pressure and has a history of cardiovascular disease as well. he recently began experiencing lower left flank pain and has diareah too. we have been to v.a. on several occasions but they say oh this is all typical stuff and he is prone to these things at his age, i say b.s., what do you say?