Actually, the IRS doesn't require anything.  The laws passed by Congress require S corporations with a profit to report a reasonable amount of those as compensation subject to payroll taxes.  An S corporation with a loss does not have to add to it by paying a salary to its owner.  Likewise, an S corporation with a $25,000 profit doesn't have to pay $50,000 to its owner just because she had a bad year.  The law requires IRS to enforce the laws that have been enacted.  If there is a disagreement about what the law requires, the IRS is required to follow the rulings of the judicial branch.  

I'm fairly sure @HOPE2 knows all this, so we should probably just MOOB.