D.S.
Having dealt with anxiety issues myself and owning a preschool with Kindergarten I do have a few pointers.
First, go over different situations with her and rehearse how she could handle them, teach her how to problem solve. Example. She may be to shy to ask to use the bathroom so ask her teacher what the process is and then go over it with her. If the teacher asks the children to raise their hand, she may be uncomfortable with that. Maybe you can ask the teacher to show her where the hall pass is and then just get up and let her know she is leaving to use the bathroom. If the bathroom is in the classroom, it may not be private enough for her and she may feel uncomfortable, so maybe she can go to the nurse when she feels she has to go, and use hers. Stomach issues do go along with anxiety so I GET that completely. Second, ask the teacher if she has a print out of her daily schedule that you can go over with your daughter at home. This will give her the opportunity to know what is coming next, hence less anxiety. I had a little girl in my prek4 who experienced the same issues, it was heartbreaking, she couldn't even transition to another classroom without a meltdown, so we learned to prepare her before all events and then talk her through it, and it really helped. We did not give in we just encouraged her. giving in will only keep the fears going and make her feel worse. Last year during our first Christmas show this little girl had to be taken off the stage she was hysterical, but by working with her and talking her through her fears by graduation in June she did a solo dance on stage a HUGE improvement!!! She just left our school and is in summer camp in her new school and mom tells me she is doing amazing!!! If you have to go to the principal to have these extra provisions approved then do it, just let them know it is temporary until she begins to feel comfortable. If it does not improve then take her to talk to a child psychologist, it will really help her, and be sure it is one who deals with anxiety. Exposure to our fears in the comfort of someone we feel safe with is the best way to overcome them. I know you want to be there for her but the best gift you can give her is the ability to learn to rely on herself. Do things with her, but allow her to do things for herself with your reassurance, it will empower her. Try not to remind her about the bathroom before school, try to tell her what she can do should something happen, go over solutions verses the problem. It should relieve some of the anxiety. If she is shy then she has to try to build a safe relationship with her teacher, so she can go to her. Maybe meet with the teacher alone before school for a few minutes each morning, until she is comfortable. It is hard for a teacher to give her the special attention she is needing with a room full of children. I am sure she will adjust, I know how you are feeling, but she will feed off of your worry, so try to not show that to her, try to be as confident as you can when you are talking to her. Best of luck to you!!