The phrase "spotty credit" refers to having a credit history that is not consistent or reliable. It means that a person has a mix of both good and bad credit, with some instances of late or missed payments.
During the housing boom, borrowers — especially those with spotty credit histories — took out ARMs in droves. (bucks.blogs.nytimes.com)
[55] It has been shown that good drivers with spotty credit records could be charged higher premiums than bad drivers with good credit records. (en.wikipedia.org)
Since you are struggling to the extent that you are seeking a consolidation loan, you may have a pretty spotty credit record already. (badcreditloanservices.com)