I would guess that after a year it is not directly caused by the Reta. Sounds more like an upset in your microbiome, or a GI infection. If it lasts more than a week or is pretty bad , or if you feel unwell or have a fever, or blood in poo, might be worth a proper medical opinion. Any travel? antibiotics? change in diet? It is easy enough to stop it for a few doses and see what happens, then maybe restart at a lower dose if it gets better with stopping. Stopping it for a while might help even if it is not the actual cause of the current symptoms.
I had something similar for a few weeks with sulfur burps that I had never had before, I think I was on ozempic at that time, I thought at the time maybe related to fiber intake, and hydrogen sulfide producing bacteria, but it went away without any answers.
Studies were done on dose changes for weight or kidney disease on Tirzepatide and Semaglutide, have not seen the Reta one but is very unlikely to be different. It was decided that changing doses for weight or anything else was not needed, it does make a bit of difference but the effect is not huge, around 30% between highest ( blood level lower ) and lowest weight persons, but individual variation in response is larger than that, and doses can easily be adjusted if needed.
