I started my second Master Cleanse on 8/16 and, on the 8th day of that, shifted to the Ultimate Cleanse (Master Cleanse with the addition of Paragon and BPs). On the second day after the shift, I started passing substances very similar to your description. The only difference is in color, mine are black/brown (but I'm also not eating). Some are "rope" (it really does look like an impression of the colon!), others just chunks.
Today is day 16, and I've been getting a good release of this stuff about every other day, it seems. My abdomen is definitely getting flatter.
roselinville, I had to laugh when reading your comment about your husband feeling you're obsessed with your poop. I've been thinking that I haven't been this concerned with feces since potty training my son! But when this is happening to you, it's almost like Christmas every time you go, cause you never know what surprise you're gonna get! My boyfriend also teases me about this, but he's fascinated as well, and I think he'll probably try the cleanse eventually.
All the best to all of us on our respective cleansing journeys!