If it's in the BTS footage. Like in Straight to the A Fujiko and Venus both have outakes with shit running down their legs. Hell you can see the roll of paper towels on the table during the Venus scene.

I remember in the BTS for Up your Ass 22 It was Teagan's first Anal and the make up lady told her to do an enema before her scene. Teagan was confused so the lady had to go into the bath room with her....But I digress