I had the same problem - felt ill from all the toxins the P&B pulled out. Don't stop or they will reabsorb into you. I'm now drinking 2-3 drinks a day with no ill-effects, but that first week I though I had caught something and all I wanted to do was sleep.
I solved the constipation by taking ~5-10 Epsom Salt pills that I make for liver flushes. I took a couple every 15 minutes or so until things started moving.
When I was doing liver flushes, the olive oil and grapefruit was bad enough. I can't drink salt water, never could, just gave up trying to drink it. So I went to the store and bought gelatin caps and filled them with consumable Epsom Salt and used those and diet dp in place of salt water. The diet dp helped the pills go down - they were getting stuck in my throat.
I know it sounds 'unorthodox', but it worked for me - 1750+ Gallstones out.
Now I keep the Epsom Salt pills handy still and pop a couple if I start to get indigestion-type problems. Works like a charm and only taking 2-3 opens up ducts, but doesn't flush you out. Takes more to unconstipate you after P&B gets 'stuck'. Keep drinking the P&B, though - it's amazing stuff. It's pulled out things I never would have imagined were in me.