There are about a hundred different operations that can be used to "remove information" from a PDF. What exactly is it that you are doing? And what kind of PDF is this. Size, and size changes, depend on contents.
Just in general, when you "Save" a PDF, Acrobat does not overwrite any of the original file data. It appends the changes to the end of the file. In theory this is an audit trail for document modifications and a way to restore a previous version (although no such tools exist for performing this operation). PDF files always get larger, unless a "SaveAs" or "optimization" is performed. Those operations merges all the modifications to create a PDF Fresco, which is smaller.
Just in general, when you "Save" a PDF, Acrobat does not overwrite any of the original file data. It appends the changes to the end of the file. In theory this is an audit trail for document modifications and a way to restore a previous version (although no such tools exist for performing this operation). PDF files always get larger, unless a "SaveAs" or "optimization" is performed. Those operations merges all the modifications to create a PDF Fresco, which is smaller.
Thom Parker
The source for PDF Scripting Info
www.pdfscripting.com
Very Important - How to Debug Your Script