Question: For years I drank strong coffee when I was teaching and when I started writing for Time-Life Books. After a few years it tore my stomach up so I switched to tea. That worked for a few years and then I got the same symptoms. So I went to decaf coffee but that didn't work because there was still some caffeine in it. So I quit drinking that kind of beverage although I found a grain substitute when working in Switzerland. Recently, I have been trying a lot of different craft beers--only one a night! Two weeks ago I tried a can of Hop Shock and after four swallows, my stomach erupted and I spent four or five hours in bed with a pan until everything was out. I have since had the same reaction with a couple of other beers--now I only drink what I know to be safe. This reaction to caffeine came on slowly and gradually and I would describe my condition as hypersensitivity. Now my question. There is a product online called Caffeine Cop--I am skeptical but if you know anything about this sensitivity I would appreciate some insight. Among other books, I wrote a physiology for nurses so I understand normal stuff but know nothing of pathology--but I can probably figure it out.