I think my left rib pain is partly constipation. I noticed that if I have regular bowel movements the there is no pain. That is just a guess. I hope you find out what is causing your pain. It sounds like yours is a lot worse than mine. I have acid reflux too and that pain causes pain on my right side according to my doctor. Acid reflux caused me so much pain that I thought I was having heart trouble. I was relieved to know it was Acid Reflex. I am now taking Aciphex . I have only taken it a couple of days so I don't feel like it is working but I am sure it takes some time.[QUOTE=fleetingfallacy;2897936]I actually have been having the same pain for the past six months or so, except the pain reaches from below my armpit to my hip, and it hurts the most around my lower left ribs. At first my doctor thought I had mononucleosis, because my throat had also been really sore at the time. I went through several blood tests and an ultrasound; my spleen was fine and my blood seemed just fine. The pain continued and another doctor I saw was absolutely convinced that it was mono, so he tried to put me on medication for it. Yet another doctor made me stop taking the medication and said that I had acid reflux and wanted to put me on yet another medication. This one, just to be sure, sent me to get chest X-rays. I went back to see the first doctor and she sent me to get a CT scan and more bloodwork. All of my tests came back saying that there's nothing wrong with me. Even now, my side still hurts. I usually can't sit still for a long period of time because it starts to hurt, and I haven't been able to do any physical labor for a while. I usually am forced to lay down every so often because it's the only time that it doesn't hurt as badly. (I'm too long-winded...)