Thank you for posting your question here, I will try to answer it as best I can.Iron supplements
can cause diarrhea/constipation
, abdominal discomfort and other gastrointestinal side effects, as such it is quite obvious that what you're feeling is because of the supplements.
Since you need the iron for your blood it cant be avoided, what you can do is talk to your doctor and ask if you increased your iron intake by eating more red meat/green vegetables is it enough so that you can avoid taking the pills.
He might say no, if your iron levels are extremely low.
I hope this answered your question.