I think you are smart to try a non-invasive solution first. I also had a precipitous drop in my Hgb, Hct, serum iron and ferritin. I used Vitron-C iron supplements and was back to normal in n no time. Invasive procedures always carry risk…. Endoscopies are not a first line diagnostic tool for low iron…. May be appropriate if the low iron is coupled with occult or frank blood being seen.