Hi All. I know this topic has probably been covered before, but I need some help and reassurance that I am not going to do myself any serious harm. I have been using large dildos for some years and can take a fist easily. But I have a problem either physically or mentally going deep. I can take a dildo 180-200 long but then I seem to hit a solid obstruction feeling very much like bone. I assume being 200mm deep I have passed the second sphincter and can only be hitting the Sigmoid. Is this correct and if so what is the best method of getting past it. Thanks for any help your advice you may offer.