Have you seen a rheumotolgist? Generally with a positive ANA you should get a referral to a rheumy as they are the specialists in that area and should be able to help figure out what is going on.
With Lupus, I have had cramping in the area where my stomach and the lower intestine meet. I can actually feel the cramp as it tightens and moves along the intestine. No one ever thought to take an MRI, I would get bloated with a bound up feeling, then when the cramp released I'd have some diarrhea.
You may not have Lupus, but with the fatigue and sore everywhere you may have MCTD or UCTD - lupus like not more diffuse diagnosis. A rheumy would probably treat -- how you react to certain meds helps narrow down the diagnosis between any of several AI diseases.
Lynnwood, Lupus & Sjogren's ModeratorDIAGNOSING-LUPUS & LUPUS-RESOURCES
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