Oldpilot,
I had the same question. If you are in pain its ok to flush before 2 weeks. The two weeks give the stones time to move down so they can be released in the next cleanse. Also like you say I would think it would be taxing on the gall bladder and liver, hense soarness after a cleanse.

It is to give time for the stones further back to move forward into a position where they can be flushed out. Unless you really can't stand it, flush every two weeks for best results.

I would think any pain would indicate there are stones ready to come out, so there's not much need to wait for them to "fall down" between flushes.

On the other hand, I would imagine the dehydration, dialation of the ducts and passage of stones through our organs would necessitate some R&R time.

This is purely conjecture, but it may be safer to do them closer together if the results were poor. I had a weak first flush, and did the second one 12 days later, partly because I didn't do the proper preparations. My second flush was a bumper crop, so I'm going to give my body a full 3 weeks to recover.