Hold it. I wish there were any other solution. Desperately hope the OB person isn't busy and can come down and break you for 5 min but they're usually busy. Your bowel habits adjust honestly.

I'm a CRNA in a mid sized regional medical center. We only trade out up to a certain point. After 8pm if I'm on call I'm the only anesthesia provider in the OR (we have one dedicated to OB but it has to be an all hands on deck emergency to ask them to come down) and so there's no bathroom breaks after that time. Surgeons, scrubs, and circulators can all scrub out and go pee but anesthesia can't leave the patient unattended, ever. Every facility is different and it's super rare for us to do cases longer than 8-9 hrs here but the potential is always there when you work in the OR.