An infection that occurs after a patient has colorectal surgery that occurs at the body site where the surgery took place. While some infections only involve the skin (superficial), others are more serious and can involve deeper tissues, organs, or implanted materials. The value shown below is a Standardized Infection Ratio (SIR), which is the ratio of the actual number of infections to the expected number of infections during the measurement period. An SIR below 1.0 indicate that the numbers of infections after colon surgery are below the number of expected infections.