Key Feature 7c: In a patient with chronic or recurrent abdominal pain: Always consider cancer in a patient at risk.
Skill: Clinical Reasoning
Phase: Hypothesis generation, Diagnosis
In a previous post I wrote something that I thing is important to elaborate on with regards to chronic or recurrent abdominal pain: "Sometimes serious diseases first present in a benign way, and only the passage of time and development of more serious symptoms or signs will provide information that declares them." In particular this is as true for the presentation of cancer as any other etiology. Cancer can be a master of presenting subacutely, often only causing problems because it's grown large enough to have consequences due to the space or the energy it consumes (ex: constipation from a bowel obstruction caused by a growth or weight loss secondary to increased energy needs of a growing mass). In the 13 year old female who I wrote the source post about, cancer would be utterly unlikely, but in those patients who are older or who have a family history that increases their risk, this would be something to always keep in the back of your mind.
My general approach to avoid missing a cancer when patients present with symptoms that could be caused by a cancer (but for which my pretest probability is still fairly low):
The Canadian Task Force on Preventative Health Care provides a multitude of guidelines to support screening efforts. Here are their recommendations for colorectal cancer screening: