>>3907
I can't believe I looked this up, the anal equivalent is called anismus, though the body of medical science tying it to gay sex is effectively zero, most proctologists believe anismus is overdisgnosed because the only way to "prove" is to shove fingers up the patients butt and they'll naturally clench up when you do this, it's impossible to tell the difference between real anismus and the patient being physically uncomfortable having fingers shoved up their butt in a clinical setting.