Can I take over-the-counter iron, like slow fe after gastric bypass surgery?

OTC iron ok. Over the counter iron is ok. Slowfe is one of most common. If you are eating ice , then you are really deficient and must take 2-3 times per day. Some bypass patient get so low in iron that an infusion might be needed. Get your levels checked!
Over th counter iron. Yes you can if you have iron deficiency and/or anaemia.