Most pills, and oils are constipating. Your best bet is to go dietary to get your extra iron.

dark green leafy veggies
red meat

I am sure a good google would help you find many others.

Amitiza is a great med, and helpful! If miralax and other interventions are not helping, give it a go, there isnt anything more miserable than being so backed up you become nauseous.

Look at places like Evitamin.com they have great supplies at great prices.

I hope you feel better.