your poop will rush through you at the speed of light, partly because dnp is an irritant (and so works like a stimulant laxative) and also because your gut flora (the bacteria that normally live in your gut in fairly hefty quantities ie 3 pounds worth) are dying and being replaced by different (resistant) bacteria that excrete toxins in your gut, making life difficult.
green poop normally means that food has travelled through you so fast that your body hasnt had time to reabsorb some of the bile salts it squirted into your gut as part of digestion. (theyre green in color). commonly you get white or grey poop when it moves very quickly also, so dont freak out if it happens.
i would be very concerned if your poop was hard, since hard poop when food is moving fast on a drug like dnp indicates a scary sort of thing - dehydration.
(meanwhile, back at the ranch, the poop is green because he's eaten 5 lbs of asparagus, and i wated my post

)