constant constipation

I am on several different meds that can cause constipation and have had the problem for 5 years after they did work on my sigmoid colon due to endometriosis.  I believe it to be the meds.  I need to use a laxative twice a week even then I need a suppository and very little comes out.  I am in no pain.  I did do a colon cleanse two years ago and it worked great.  Is there something else you could recommend to try ?  I do use 3 stool softners a day and try to drink 2 liters of waters most days.  It's just like nothing moves. I have heard of a sluggish colon before.  Any ideas would be appreciated.

Thank you for your time and considration.

[dinkster]

Try mirlax