<<Disclaimer: Verify this information before applying it to your situation.>> For years, every time I would give a urine sample, I would be told, there are a small amount of red blood cells in there. One of the major causes of trace blood in the urine is ... celiac disease. It's called IgA nephropathy - the IgA antibody/antigen complexes get taken out of one's bloodstream by the kidneys, and they do micro-injuries to the kidneys, which bleed. It might even be *the* main cause. Celiac disease is so terribly underdiagnosed. Once a nurse told me, "some people just have blood in their urine", like that's just a personal idiosyncracy. BS. This fall when i went in with a bladder infection, I was cheered in the middle of my bladder infection when the doctor told me there was no blood in there. I had been more cornfree than before - I'd been eating vanilla powder, which is just ground up vanilla beans, rather than vanilla extract, rather little accidental corn syrup otherwise. I get the vanilla powder from Bob's Red Mill. http://www.bobsredmill.com Then after a couple of courses of antibiotics, I went in with back pain again - the back pain is also a food intolerance symptom and it might have been partly caused by corn reaction - and I was told there was trace blood in my urine again. Because of corn starch in the antibiotics, I'd had another corn exposure. I'm practically sure, not a gluten accident though. I think what probably happened was that my kidneys were getting hurt by IgA antibody/corn complexes. I didn't actually feel bad on the first two courses of antibiotics, only on the third I had symptoms that suggested a food reaction. Some brands of pharmaceutical grade corn starch have less corn protein than food grade corn starch, some don't. It suggests to me that you should regard trace blood in the urine as a possible indicator that you're eating something that you have an IgA food intolerance to, it could be gluten or it could be something else. And this symptom might be more sensitive than having overt reactions. Laura *Support summarization of posts, reply to the SENDER not the CELIAC List*