Trazodone muscle spasms/tightness?

Hi, I started taking Trazodone (Trittico) in January this year. I started with 50 mg (daily, before sleep), 2 weeks later increased to 100 mg. In May I increased the dose to 150 mg.

Since the end of February I started experiencing muscle spasms, namely Pelvic Floor muscles tightness. It was not that severe and quickly resolved. But in July it returned and still persists. The symptoms are: difficult to pee, to defecate, abdominal pain. I was examined by proctologist and he said that I don’t have any pathology except for spasm. So this is some kind of functional disorder.

I’m trying to find the reason for that. The only drug that I take daily is Trazodone 150 mg. So I’m curious if anyone has experienced similar symptoms. I didn’t find them as common side effects in Trittico’s description, so this seems unlikely, but anyway I want to double check.