have you tried the salt water flush? You must have heard about it since it's often past of the master cleanse. In case you haven't, it's tobe done first thing in the AM, before having any water. Make sure you are well hydrated, the day/night before.
I've never known this *not* to work at moving the bowels.
2 tsp. of Sea Salt (but not the white stuff they sell in bulk health food store bins)
celtic, or himalayan...or Redmond...
I like celtic for the mild taste.