She had to go so bad she couldn't even hold it all the way in - that turd was already groundhogging while she was setting up, and you can even see a bit had already fallen out. She tries to clench her asshole at the start to show how badly she needs to go but she can't even close her asshole. She then releases the massive turd, along with a bit of piss she was also holding in because should could not have let her piss out without the turd also coming out.
