Joints Pain, Dizziness, Nausea And Strange Bowel Pattern. What Can I Do?

My daughter is 14 and has been complianing of stomach pain and some nausea , dizziness (not constant, but on and off) achy joints and mucles, fatigue , and she is having a strange bowel pattern. She can go for almost a week with out having a bowel movement . Then she will complain of nausea and intence cramps and have diarrhea . She also had a deep marron colored diarreah a couple days a ago as well. When she does have a solid bowel movement it will either hurt her because it streaches her anus farther than it should, or there will be almost nothing there. I might just be a nervious nelly here but I m concerned and money is tight so unless I make an oppointment for a couple weeks from now it will be considered an emergency visit even when she sees her GP. I was just wondering if I should take her to the doctors where the emergency room would be something to go to. Or her GP , at this point I just don t know. And her depression has been a bit worse than normal, if that helps at all. But if you could get back to me ASAP that would be great Thank you