I had this problem. Actually got so backed up I wasn't able to digest and ended up throwing up. Tmi. Sorry. Prune juice really really works!
It doesn't get any better ugh
Take 2 or 3 Colace stool softner a day and take a fiber supplement. (No laxatives)
Prune juice, plumms, allot of water, oatmeal, mini wheats...I've finally started to be moderately regular. I have prune juice but light prune juice (taste a thousand times better) in my house at all times.
Prunes, prune juice, milk of magnesia.
Eat foods high in fiber, drink more water, exercise.