DocumentQuery with multiple related document types

I have a DocumentQuery I'm using to get 2 different types of related documents and I'm not seeing a way to do this. Ideally I'd want something like this:

 ...
 .InRelationWith(ValidationHelper.GetGuid(physician, Guid.Empty), "isrelatedto", RelationshipSideEnum.Left)
 .InRelationWith(ValidationHelper.GetGuid(specialty, Guid.Empty), "isrelatedto", RelationshipSideEnum.Left)
.OrderBy("DocumentName")
.Published()
.Columns("DocumentName", "NodeGuid");
...

My results are only showing the last entry. So if the specialty variable does not have a value, it doesn't get the related physicians.

If this isn't possible, what about merging the DataQueries?