Oily, Bloody stools, cramping, nausea

for years I've had these GI problems and I'm not sure if it's celiac disease.  I've had exhaustion and cramping and nausea with these bloody oily stools.  does this mean I can't eat gluten, rice, wheat, bran?  
can you diagnose based on a blood test?  my upper stomach feels sore when I drink cold liquids and I have GERD
I also think antibiotics makes the nausea worse
I've tried nexium, zantac, prilosec, but the best thing I've found is probiotic tablets and yogurt and fiber powder.

[ill13632]

my whole upper stomach feels sore when I drink cold liquids, is that from GERD or something else?
thanks

[ill13632]

I started taking l-glutamine because I heard it helps the gut lining.  do the probiotics kill the bad bacteria in your gut?  does it matter which probiotic you take?