Manage student bathroom breaks by giving each student a bathroom pass with their student number on it and setting up a basket for students to drop their passes in as they use them. Students can use a free pass to use the restroom during class time by dropping a pass in the basket by the door. You can print more than one copy depending on how many passes you want each student to have. Passes can be given daily for younger students or weekly for older students. If they don't use their pass(es) all day (or week) you can reward them. If they run out of passes and still need to use the restroom you can charge them class tickets, class bucks, etc depending on your management/reward system. Simply assign a class job to return passes at the end of each day or week. I suggest printing on bright colors and laminating.
I have included student numbers 1-40
*You can shrink them smaller in print settings to whatever size fits your needs (I print mine at 85%).