Frankly, I would be very careful about using Cascara Sagrada or Senna for more than a week at a time. Some people tend to develop a lazy colon and become dependent on those herbs in a fairly short time. I think it might be a good idea to take a rest from these particular herbs after a week of usage and make sure your bowels will move on their own. I do believe in doing a good Colon Cleanse with a parasite cleanse, and then continue the Colon Cleanse for at least a week after the parasite cleanse is complete.
The white bits may well be parasites, I have heard others mention them. If it looks like rice, it may be Tapeworm fragments; peanuts may be flukes. Its a good thing you are expelling them. Be sure and drink plenty of water when you are using psyllium.