Take the prescription for now, but read your hospital's endoscopy instructions on what medication has to be stopped prior to having the procedure. Even a few days of taking the iron supplements may help you. It can cause constipation in some people though!
Coeliac Disease is an autoimmune condition and uses a different mechanism to the one that absorbs iron in the gut.
Untreated CD, inhibits absorption of a lot of vitamin and minerals - so if you did get diagnosed as a Coeliac, you would initially need to take that prescription more than ever.
Just a thought, have you had your thyroid tested? Also thyroid antibodies to check for Hashimotos thyroditis? It's an auto immune condition where you must avoid gluten so could be a possibility. It also could be the link to your low ferritin.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.