If the US government had their way no one would use intestines for sausage, but the good stuff is always in intestine skins. If you're smart you purchase your meat from a reputable source or have it processed locally in which case all sausage will be done this way.
I am quite sure that most people in the US don't even know that sausage casings in fact are traditionally intestines.
On the main subject though, what you in the UK seem to be calling bacon appears to me to be a belly/side cut with the loin attached. Here in the US we generally get pork belly for bacon. Now I would not say either are wrong, but would instead challenge your Brits to leave the loin whole and either use it for a roast or slice them about an inch and a half thick(3cm?), wrap them in thick sliced belly bacon, and cook them to medium in a hot cast iron skillet. Get the best of both worlds instead of the moderate.