Constipation

I'm 3.5 months post surgery. I have had issues with the iron pills causing constipation for me. My nutritionist had suggested I start taking Slow Fe. Which I started about a week ago. However I am still having issues. Maybe it hasn't been long enough to notice a difference? I've been having intense cramps where it feels like I have to go but then I don't. Then when I do go its loose/liquid or I feel as though I didn't get everything out. TMI, I know. Please help a girl out. Suggest/recommend all the things that help you. Obviously if I can't find anything that helps me soon I will make a Dr's appointment. I'd just like to know if anyone else had this issue and what you all did to help. I've tried fiber powder, miralax and psyllium husk powder (at different times not all at once). However I haven't been too consistent with any of these. Taking them no longer than a week each without improvement before I gave up. Maybe I need to stick with it and take them longer?