What Causes Recurring Spells Of Dizziness With Dark Urine?

My husband is 47 has recurring dizzy spells leaving him extremely week and tired. He also has severe night sweats and stomach discomfort. His urine is very dark almost a redish color and his breath smells like he is ill. About ten years ago he had a full gastric by pass and drinks about 12 beers or more a day. He is refusing to go see a doctor but I feel there is something serious wrong can you give me any ideas what it can be?