Hereditary colonic polyposis conditions are all characterized by high rates of cancer, but they have diverse phenotypes, genetic heterogeneity, and assorted inheritance patterns. The most well known of these conditions include familial adenomatous polyposis, attenuated familial adenomatous polyposis, MUTYH (MutY human homolog)-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and Cowden syndrome. Early recognition of these conditions is not only vital for management in affected individuals, but also for prevention and early detection in at-risk relatives. Reviewed here are the genetic testing strategies for colonic polyposis, as well as an overview of characteristic features and management considerations for these syndromes.