What is medical Interfiling?
The interfiling simply means that you send the documents as per your wish and then request USCIS to add them to your file. All this is done without USCIS requesting these documents through the official process of RFE (request for evidence).
What happens when USCIS rejects an application?
If USCIS rejects your application for adjustment of status, and you don't have a valid, unexpired right to be in the United States, most likely under a visa, USCIS will send you into immigration court (removal) proceedings. There, you will have the "opportunity" to have an immigration judge hear your case.