I have been having issues for over a week now. 
It first started when I got these horrible stomach pains. That later turns into my lower back feeling like someone is pinching every nerve and then my knees did the same thing. Because of the pain, I got sick to my stomach and am throwing up stuff that should have already been digested. And yes, it was coming out the back too. The next day its just severe cramping in my gut/back/knees. That's when I noticed that my monthly visitor started (even though its not my normal cycle). The pain lasts for about 3 days all together. The pain went away for the most part, but I still get these odd bellybutton cramps and I still feel nauseous almost all the time. Now it seems I have a cold type thing that came out of nowhere, and that is not helping at all. My diet hasn't seemed to change; I still eat the same amount. But things that normally don't make me sick are making me sick. And I am still dealing with my monthly visitor. 
If anyone has any idea what could be wrong, I would greatly appreciate any information.