The Omnipresence of Cancer is a theory used to describe the experience of having colorectal cancer. It provides a framework that can be used by colorectal nurses to provide individualised and evidence-based care to patients diagnosed with the disease. The theory maintains that thoughts about colorectal cancer are omnipresent (existing everywhere at the same time) in a person's life from confirmation of the diagnosis throughout the remainder of the person's life. If colorectal nurses are not familiar with the issues underlying this concept, they will be unable to adequately plan patient care.