I went 17 days without pooping at one point so I know this pain well. LOL. I take Colace twice a day now and a Mag Citrate PILL (DO NOT GET THE LIQUID) in the evening. If I happen to go more than 3 days without going, I take some Milk of Magnesia. Smooth Moves tea works, as well, but I've found MoM to be better. You can also have Miralax twice a day... just add it to WARM drinks and not cold because it is not unflavored, despite its claims. lol. Miralax is meh, though.
I was told not to take fiber because it is bulking. I had a hernia after surgery, though, and that may play a factor into why I was told no fiber supplements.