I took an iron pill for years then got to where I couldn't swallow it any more - it was a horse pill and tasted nasty.
When my iron has been really low they have given me iron via IV.
My iron is really low also. I take Feosol Ferrous Sulfate. I take 2 pills a day, one at breakfast, one at dinner. They are small triangle shaped. They don't cause any stomach irratation, at least for me. I've notcied a huge improvement, not as tired.
Hope that helps!