Hi,
you can do it using an action list or activate the check in the preflight profile. It depends on which version of Pitstop Server you're running.
The preflight check can be found in the 'Page settings' category (second check). You set your area from a margin within the trim box to the bleed box or a margin outside the trim box. Any object located in this area will be reported.
The action list is a bit more complicated. the action you need to use a couple of times is the 'select objects inside/outside region'. Here you can set up to look inside or outside a page box.
e.g. find any object in between trim and bleed box
select objects inside/outside region (outside trim box)
select objects inside/outside region (inside bleed box)
AND
log selection
I hope this helps,
bert