Two blood tests indicating possible celiac? That's useful information, though like many tests these aren't necessarily conclusive. If you decide to go through with the biopsy it may tell you if your case is very advanced. However, if it is negative you most likely still have a gluten problem, judging from your description of symptoms.
Personally, I would skip the invasive test and put myself on a strict no-gluten regimen to see if that clears up the symptoms. If your symptoms go away, ta-da! there's your diagnosis.
Actually, I did that--a number of years ago I had unexplained symptoms (not gastro, though). I sent for the Dr. Fine stool antibody test (EnteroLab) which again, like many tests, may not be conclusive. However it showed my gluten sensitivity was high, and my DNA includes the worst combination of gluten-sensitivity genes. Plus, my brother was diagnosed celiac (blood test) and my aunt is a diagnosed celiac. Hmmm.
So I started eating a gluten-free diet, being very careful to do it correctly. The result? My symptoms did not improve. I had to keep searching for the cause, and after another couple of years of going to doctors finally found out I have Lyme disease.
Interestingly, because Lyme disease damages your system in so many ways, doctors often tell their patients to go gluten-free during treatment. So, I have just continued this diet as a precaution. Some day, when my health is recovered, I may try eating gluten again. Or on the other hand, I may decide that my DNA is against me and it might be wiser to just stay off it.
Anyway, it's not so bad once you get the hang of it. Why not just give it a trial and see what happens?
10th yr on program: age=58, BMI=18, b/p=110/70, tc=126, McD=100%.
diagnosed with lyme disease March 2010