Oh my heck...yes they will not pull the bank statements, they will have you furnish your bank statements, Retirement information statements, Statements on any debt you might have, paycheck stubs. They will pull your credit history and fico score.
AND, they may have you furnish this information several times and often won't give you much time to get it. They do use the information you give them, but you will most likely have to go to the bank and get a very official copy of the information or have the bank send them a copy.
Here is what I did when I was doing my mortgage. I went in and talked with the Mortgage lender. I had her make me a list of what information she would need and I gathered it all together and took it to her. That said, it took me a while to find my house and so because so much time had passed I had to furnish all the information to them again.