Then you are using Scrum to obfuscate a core communications problem in your company. Either the business people are clueless about what they want and are flailing around in a panic, or they are not able to communicate their needs to you properly, or you are unable to understand their real business requirements, or they insist on micromanaging every aspect of your product. Or some combination of these factors.
You should not have to "fend off" your professional colleagues, you should be able to have an adult conversation with your peers and frame requirements and expectations accordingly. If your company culture prevents this then that's what you need to fix, not further burden the team with the demands of Scrum.