Some of them are notorious for 'clogging' things up terribly.
To help with this, start out with Colace or PeriColace and lots of fresh fruit and/or a high fiber cereal such as Fiber One http://www.fiberone.com/product/cereals.aspx -This one packs the most benefit for the least amout of cereal. I only need a half cup of the 'original version' to work things thru.
Having been on serious pain meds for extended periods of time, I have to tell you that taking such precautions are essential to avoiding other colon issues in the long term!
Avoiding this problem by starting BEFORE any procedures is pointless now? But if, in the future you are going to have more or any other type of surgery? Start a week before...just to keep things happy and life painless.
Now, if you have issues about eating some fruits or fiber cereals [diabetes or gluten, for example]? I guess you should check out Gluten issues and diabetic issues in those forums.
It's not FUN! It's worrisome and at times painful. Precautions are the best way to avoid these things... And, you need those pain meds until you are healed. I hope both will become non-issues and soon! - j 's