I have a feeling that your answer is #2...just because the toxins DO get stirred up pretty rapidly with the b&p's (and your clean diet, too - go read rawfaith's post on the Raw Food Forum - read the link she gives to her story...how just eating raw made her have flu-like sick symptoms...then when she got over that big toxin release she felt like a new person!)....I know that I get pimples right away when taking the b&p's (within 2 days there they are - that's fast!). So, I think you are absolutely correct in saying that the constipation is trapping the toxins and not allowing them out of you! You've got to get your bowels moving or you're going to feel crummy with all those toxins not being released.
Like you said...drink more water...start your day with warm water in the morning. (2 to 3 litres of water a day is ideal) I like Ocean's advice about liquid minerals.
Does anyone know if Udo's Choice is 'liquid minerals'? I've been confused about this for a while.
A good oil is great for constipation too! (flax seed oil, Udo's choice...)