You cannot help an alcoholic until they are ready to help themselves. For the indigestion the best bet since he is refusing medical treatment would be to try one of the over the counter medications available for GERD such as Tagamet aka cimetadine, Zantac aka ranitidine, Pepcid aka famotidine or the newest one Prilosec. It would be a great idea to get this checked out by the doc to find out what is going on but since you said he refuses treatment then these are the best things for him to try.