Hi. I don't have any real answers for you, except to share how I dealt with my elimation problems on the MC. Despite the assistance of salt water and/or Smooth Move Tea, I was not really eliminating well on days 4 thru 7, and on days 5 & I took the P&B shake, which I think really bound me up.
I had a colonic (my first!) on day 8. It helped clean me out, and now on days 9, 10, and 11 of the Master-Cleanse I've been having successful eliminations with the help of Smooth Move tea.
So, I guess with my limited experience and knowledge, I'd suggest a colonic because it will help cleanse the colon a lot higher than an enema can reach. Also, the colonic tones the colon walls. PTree could probably provide better counsel on this than I.