I have a lot of problems attending medical appointments - people touching me and poking around inside often makes me distressed and gives me flashbacks. I've created a little letter that I copy & give to health professionals whenever I have to go for an examination. Feel free to customise and use it for yourself.

Dear Doctor/Dentist/Health Professional
I am a survivor of sexual abuse/sexual assault/sexual violence. I can sometimes become distressed/panicky/upset during physical examinations, due to the nature of the abuse I survived. This can be especially bad if medical/dental instruments are placed inside or on my mouth/backside/sexual organs. Please tell me what you plan to do BEFORE you do it. Please give me a way to notify you that I am in distress. STOP and step away if this happens (unless my life is in immediate danger). Please do not ask me to explain the details of the abuse during the examination. If I need to tell you, I will.
Thank you for reading this.
Your Patient/Client