I had a lot of that come out when I did an enema and I have a 17 year old who did 2 courses of accutane that fried his insides and today when I was rummaging through poop to do his stool test (for parasites) it was like completely black with a million mucous strands in it. Accutane is linked to crohns and ulcerative colitis, so I think thats where the mucous is coming from. The kid already has issues, so it will only get worse. I think mucous is made in response to irritation.. so something is goingon, especially if you're having pain. Did you have your gall/liver checked too? Your poop color looks a bit off to me. Like there's more gold in it than it should be