fasting and motility

hello im about to start a juice fast for both health and weight but on a three day test i noticed my bowels stopped moving and felt alot of lower bloating that went away once the got moving again...i do have bacterial issues in my lower bowl and gallstone issues so i feel its important to keep them moving while i fast...what are some methods of doing this...inulin fiber? herbs? flushes? more? one better than the other?

thoughts?

thanks