I just started taking Effexor XR on Thursday 4/13. I have not felt any positive change yet for my IBS (C with ab. pain). I am staying positive an plan to stay on it for at least a month or so. MY GI and doctor have ruled everything else so it must be anxiety or depression I am told. I have noticed not being able to get into a deep sleep. Is this normal, and does anybody out there taking Effexor remember how long it took for any change. I am on 37.5 mg for one week and then it ups to 75mg a day. Thanks,Steve