An incisional hernia is a type of hernia that occurs at the site of a surgical incision or scar from a previous abdominal surgery. When a person undergoes abdominal surgery, the abdominal wall is weakened and can sometimes fail to heal properly, leading to a weakness or gap in the tissue. This weakness allows organs, such as the intestines or fatty tissue, to protrude through the abdominal wall, resulting in an incisional hernia.