Hi hugs - it is internal manipulation so what a physio might do on the outside but inside the rectum. You really need to find someone you trust and feel comfortable with. Thankfully the person I found is wonderful. It is an hours drive but worth it. She is now doing acupressure externally to calm the nerves down - she uses what looks like two pencils! It seems a bit hippy and alternative but the combination is helping me and my pain has decreased significantly although its taken several sessions to see an improvement. I think is same as pelvic floor therapy if you google that. That's all I did in the end use google.
https://pogp.csp.org.uk/
these people sent me a list of people in my area.

Thank you SueMac. I am pleased that you have found treatment that helps you. Pelvic floor physios are a rare species and good ones are worth their weight in gold.

Indeed they are. Hard to know if it’s the therapy or just time which is helping but having said that I was getting nowhere before I started seeing her.