Very doable. As stated just takes practice. I have done this several times while enjoying myself. Enemas, plugs, dildos, baby bottles, double dildos etc.
I think it's fake too, but I can't figure out how it was faked. But it has to be, that dildo is so long and that it would have to go into the large intestine and cause it to bend out of shape. Painful much? Still can't figure out how they did it on an amateur porn budget...
By fake I mean all acted out. Also, I view any porn where they pull out for the 'money shot' as being fake as the natural instinctive urge is to thrust as deep as possible to maximise chances of a successful conception. Unless one is using the withdrawal method of contraception (which has never been that reliable) then withdrawing for the sake of displaying the ejaculation to the camera is fake, and very predictable. I find the best ones are those which are usually homemade amateur videos of couples enjoying real sex to full completion, usually referred to as Creampies. Another I like to see, although extremely rare, is where condoms are used, also to completion, when the penis is retracted, along with the semen in the condom. However, whenever condoms are used in porn videos, you can pretty much guarantee that they will be whipped off at the last moment & ejaculated into the recipient's mouth. As I said - very predictable.