Welcome @borna02. I added your question to the Ostomy support group too (https://connect.mayoclinic.org/group/ostomy/).

It sounds like you're having a struggle with bowel movements since having your stoma closed almost a year ago. And, of course, long term antibiotics hardly seems like a permanent solution. I wonder if @dval or @martinkda may have some experiences to share with you.

Mayo Clinic currently has 3 clinical trials open looking for treatment solutions:
https://www.mayo.edu/research/clinical-trials/search-results?studySiteStatusesGrouped=Open/Status%20Unknown&pocId=CON-20306105&_ga=2.239710016.270384143.1655825164-1419036637.1645131510&_gac=1.150072132.1654865185.CjwKCAjw14uVBhBEEiwAaufYxzSX9eBgIznhbFkIMFapSEXhrjQx462vUvCuft8CstsDub4YSkigZxoC-VEQAvD_BwE
Borma, do you also experience pain or is your main concern loose and frequent stools?