I would suggest seeing a GI doc for your symptoms. A lot of them sound like my daughter's complaints and she was diagnosed with Crohn's last year after endoscopy/colonoscopy. Do you ever get unexplained fevers/chills? When my daughter started to have these, along with being fatigued and looking sooooo pale, I knew I was dealing with more than just belly aches/pains/diarrhea (which we thought was an ongoing stomach virus...) She had no energy, didn't want to play with her friends, didn't want to eat much, etc.
What you're experiencing may be Crohn's, but no one here can really tell you that. I hope you see a doc and that you are feeling better soon!
Oh...and here's a test I just read about for Crohn's: PROMETHEUS® IBD Serology 7 is a test to help your physician determine if you have Inflammatory Bowel Disease (IBD), and if so, which type: ulcerative colitis or Crohn’s disease. Test results may provide your physician with prognostic and other useful information, and help determine the best course of treatment.