What I DID experience last time was very mild mini-attacks after doing the cleanse for about a week, usually at night just before bed. This is when the GB is quite packed with stones, you can't flush them all out in one go. The stones you flush out make room for more to loosen and move forward. That's why it's important to keep cleansing until you really feel stone free. I've just done a follow up cleanse and I feel great now. The pressure is gone and I'm feeling much better.