Adjective describing something that has been rummaged through

Solution 1:

Since KannE seems reluctant to add an answer...

Ransacked. Like disarrayed, wiktionary doesn't think it's an adjective, but the verb has the right connotations:

To make a vigorous and thorough search of (a place, person) with a view to stealing something, especially when leaving behind a state of disarray.

In fact, this is virtually an exact match for "something that is in a state of disarray (because someone has been rummaging through it)".

Solution 2:

You can use "rummaged-through" or "rummaged" adjectivally:

I looked at the rummaged-through / rummaged drawer with suspicion.