Chad Callihan has a way to search the text of stored procedures:
Story time. Let’s say a database server is receiving a new release that include a change to a stored procedure. All of the databases are supposed to get the changes but one way or another there are problems with the release and it has to be stopped part of the way through. Maybe some changes got rolled back but others weren’t rolled back. We don’t have accurate logging of what databases have been updated but we want to know if a stored procedure is on the old version or received the new version.
I’ve used this technique quite often. The only downside is that if you have a lot of procedures and don’t specify the object ID, search can get a bit slow.