said by jjoshua:
As long as the pipe is exposed and you're doing work, you might as well put a camera down the pipe to see if there are any other problems.
I have looked down it as far as I can see, and don't see anything other than very light curtains of roots at some joins. The kind of thing that rootx should take care of. Water certainly flows like there's nothing in it's way. I don't own a camera that I could actually send down the pipe, I'd have to rent one or hire someone with one. The washout is full size though, so sending a camera down it should be no issue if it's needed in the future, so I don't think I'll worry about it right now.