"Crap up" is a colloquial term that can be used to describe a situation when things are done poorly or when something is ruined. There are many synonyms for this term including "mess up," "screw up," "botch," "flub," "fumble," "bungle," "muddle," and "slip up." Each of these words emphasizes a different aspect of the mistake or error made. For instance, "flub" implies a slight error, whereas "botch" emphasizes a major mistake. Regardless of which synonym is used, all of them express the idea that something has been done incorrectly or in a flawed manner. So next time you need to describe a mistake, consider using one of these alternative expressions instead of "crap up".