i will just say what i would recommend:))
first prescribe proton pump inhibitors and se after a certain amount of time if he feels better if not i would do a esophageal ph test that can diagnose it also lesions and signs of gerd can be seen with endoscope.
So as a doctor antiacids ,proton pump inhibitors and also an option are h2 receptor antagonists . As a nurse recommedations on his diet no coffe smoking juice .