Data confirm that vampires are living longer these days, which makes it necessary for them to undergo the same preventive screening measures (maybe even moreso) as the general population. Colon cancer being the third most common cancer (and resulting cancer deaths) in males and females makes it that much more of a public health concern for vampires and mortals alike.
If you are a fan of Bram Stoker or the "Twilight" series then you will agree that vampires are an asanguinous species. The argument to support this claim is based on the fact that their very survival is dependent on ingestion of human blood; given that human blood is not endogenous to vampires they require it in their diet, much the same way mortals rely on plants and animals for their supply of Folate or Vitamin B12.
Predicated on the fact that vampires have a digestive system, the current recommendations of the United States Preventive Services Task Force for colon cancer screening presents a bit of a quandary for the concerned vampire. It would behoove vampires to stick with the gold standard for colon cancer screening and simply opt for a colonoscopy starting at age 50 and every 10 years thereafter.
Although, they can choose to have a sigmoidoscopy (looks at only the sigmoid colon and rectum) accompanied by fecal occult blood testing (checks for trace amounts of blood in patient s stool) there are obvious drawbacks to this. Unless the vampire has recently fed, the fecal occult blood test would always yield a negative result rendering the test not only completely useless but also a major healthcare disaster in a vampire with precancerous polyps. Additionally, they would have to get this test performed every five years. If you have the lifespan of a vampire, you can imagine that this obligation may prove burdensome, especially in light of the fact that many endoscopy clinics only operate during daylight hours. Sigmoidoscopies have the potential to miss the presence of lesions as 50 percent of them occur above the level of the sigmoid colon.
Colonoscopies would be a no-brainer for vampires as they are well ahead of the game and are not subject to the horrors of going through the bowel prep process. This is when mortal patients have to drink a gallon of a fluid known as Go-Lytely (clearly a misnomer) in addition to restricting their intake of solid foods, from the afternoon onward, the day before their colonoscopy. Mortal patients are required to fast after midnight the night prior to their procedure. This aids in the visualization of the colon by the clinician.
Vampires can rest assured that they had the best possible procedure available when opting for a colonoscopy. It is without a question, not only the gold standard, but the only viable option when ruling out cancer in this subsection of the population.