Jim
                    
                    
                    
                    
                    
                    
                    
                        
                        
                        Hi.  I am 19 years old and have had the same experience.  I drank milk since I was a baby, and never had any problems, but, after a year at college, not drinking any milk, I came home to find I couldn't drink a glass without vomiting within an hour or so.  Peculiarly, though, I have never thrown anything up, as any food I have eaten seems to be digested by the time I encounter any symtoms.