The problem is that it's a nice red brick wall in full view of the rest of the house, so butchering it isn't the ideal solution, otherwise I'd have taken an SDS chisel to it a long time ago. Given that most core drills around this size are a nominal 120mm (and given that the hole was already made at great effort and can't easily / tidily be increased), the flange of most push fit couplings won't fit into the hole. On the other hand, solvent weld flanges will fit into the hole.
Here's a "CAD drawing"(??) from Floplast (actually little more than a basic Autocad line drawing), showing a typical solvent weld bend. This will fit the bill, as I will be able to get the flange into the hole in the wall.
From a building control POV, you have either need an access cover on the bend, a dismountable push fit connection, some other means of rodding – or accept that the coupling will have to be replaced if access is required. In this instance, the indoor side is easily accessible (remove the toilet connector) and there is a gully immediately adjacent. Not ideal but the alternative would be to lift the blockwork and start excavating the pipework. As I said, I have a life to live and swarf to make, so we can forget that idea.
As you say, Alan, it's not unusual to have the soil stack close to the wall. Often the toilet connection hits the stack from the side, some way from the exit – giving you an inch or two to accommodate the bend flange either inside or outside the wall.
Murray

Edited By Muzzer on 29/01/2017 00:18:19