What we were called out for
The customer called because the toilets and the sinks had both started draining slowly. When more than one fitting slows down at the same time, the problem is rarely any of them — it is usually something further along the run that everything drains into.
What we did
We lifted the manhole cover to see where the water was actually standing, which tells you straight away whether the blockage sits before or after the chamber. In this case it was a build-up of toilet paper that had collected and stopped the flow. We cleared it and ran the system through to confirm everything was moving properly again before we left.
The result
Flow restored and the toilets and sinks back in normal use before we left, cleared up behind us. Paper build-up like this usually means the flow through that run was already a little sluggish, so it is worth keeping an eye on — if it comes back in the same place, that points at the pipe rather than what is going down it.