1)It is אסור to Daven if you need to go to the bathroom, if you need to go, you must go to avoid any ספיקות 🚽💩

2)If after שמונה עשרה you go to the bathroom, and you wondered if you needed to go before davenjng, if you go back and realize you could’ve held it in for 72 minutes, then you’re good, if not, you must repeat שמונה עשרה 🔂

3)If you realize you’re going to miss the זמן of תפילה , you should try to Daven even if you need to go a tiny bit, but if you make the חשבון that you can’t hold it in for 72 minutes, then you should go to the bathroom. It’s better to Daven by yourself when not needed to go to bathrooom opposed to with a ציבור when you do need to go ❌🙏🚽