Two over-the-counter suggestions come to mind. After surgery I had such profound constipation that at the 4 week post-op point I had to be re-admitted to the hospital to get it resolved. They gave me a dose of magnesium citrate. This is a liquid, industrial-strength laxative that can be purchased at the drugstore. You just open the single serving bottle and drink it. I could only get down about half the bottle (the taste was nasty), but it really worked! After that success, they sent me home with instructions to take Miralax (another over-the-counter laxative) per package label dosage, daily. Once things began to return to normal, they told me to taper off the Miralax, taking half a dose for a few days, then one-fourth of a dose, then none. After that, they recommended a stool softener as required.
Unfortunately, although all of the docs and medical staff know that the meds given during and after surgery can cause really nasty constipation, they don't have any way to know in advance which patients will be most severely affected.
I don't want to scare you, but in my case the situation was so bad that it caused a tiny abdominal hernia to enlarge, eventually requiring surgical correction about a year later.
Be sure to drink plenty of fluids, as often post-op diuretics can dehydrate you.
Ask your doc about mag citrate. That was the fastest and most certain relief for that problem that I've ever had. No lingering after effects, either. (Although there may have been some lingering after effects for the poor nurse on duty. I still remember her walking past the bathroom door and exclaiming "Oh, my god!") ;-))
Also, remember that even this is quite common. The topic comes up for discussion a couple of times a year and people are warned about the possibility, but then it drifts off the radar screen until some other poor soul falls into it.