Swallowing pain

Hi, I was wondering if anyone has suffered anything similar to me. I am a 26 year old male, and for about the last four months I have been suffering from occasional pain/discomfort in my lower right hand side, generally more towards the back, which is heightened when swallowing cold liquid. I will freely admit that I probably drink a little more than is recommended (although only really at the weekends) and I suppose I did go a bit nuts in my uni days, so I was immediately concerned about the possibility of liver disease. I went to my GP who felt my tummy area and found nothing untoward, and I had two complete blood count tests, both of which came back normal. He suggested it was esophogitis and told me to try taking zantac. I also visited a different GP as a visitor in my parents' town, who again had a feel but said everything seemed normal, and the complete blood count test I had through him came back fine as well. I went back to my own GP who still maintained esophogitis and put me on a month's course of ranitidine, which eventually seemed to make the pain subside. About two weeks after completing the course the pain seemed to come back although again it was more of a discomfort than actual pain. I went back to my GP and he has prescribed a month of rabeprazole, which I started five days ago but am yet to feel any benefit. I must emphasise that this pain/discomfort is only really noticable when swallowing cold liquid but it can be a little alarming, especially because I do feel that I drink a little too much if only socially, and I don't know if I'm worrying over nothing following the normal blood test results and nothing being picked up physical examinations. Should I ask for a biopsy or a scan perhaps? Any comments would be really appreciated. Thanks.