Dougal mentions Lucky Charms, which are not popular in the UK or Ireland. Graham Linehan admits that was his own mistake, due to his obsession with American movies.
Mrs Doyle mentions that she's off to "St Patricks Hill" for a Lenten pilgrimage. This is a parody of Croagh Patrick in County Mayo in the west of Ireland. On the last Sunday of July every year, people climb the mountain, sometimes following the tradition of climbing it barefoot!
In the script, Jack reacts to Sister Assumpta's arrival by saying "I'm going for a wank." Ted attempts to clarify to Assumpta that he means "going for a walk", only for Jack to then shout out "Nobody come upstairs while I'm having a wank!" - this was deemed too lewd, and replaced by him throwing himself out of the window when he finds out that Assumpta is a nun.