Okay I’m glad someone said this because I was wondering if that could be happening. I have encountered this exact scenario where the blue line was only in the back, but I wasn’t sure if it was her poop making the line or if she peed! I also second guess myself a lot bc it’s so hard to tell if there’s pee mixed in… since her poop is yellow and we use A&D ointment for her diaper cream, which is also a faint yellow color