Perhaps I shouldn`t have said Can`t go back etc. 
You can go out through the wall -run along outside and then back inside to your internal soil pipe . I meant it would look odd @ least and have a number of bends . I wouldn`t do it . I`m confused myself now
You can go out through the wall -run along outside and then back inside to your internal soil pipe . I meant it would look odd @ least and have a number of bends . I wouldn`t do it . I`m confused myself now 