February 2023 – Clinical Informatics

A 45-year-old Caucasian man with no family history of colon cancer or risk factors just underwent screening colonoscopy. During that colonoscopy, three polyps (endoscopist noted A: 3 mm loop; B: 4 mm loop; C: 9 mm loop) were taken from the right/ascending colon. Pathology found that A was a tubular adenoma with low-grade dysplasia, B was a tubular adenoma with low-grade dysplasia, and C was a tubulovillous adenoma characterized with low-grade dysplasia. 

Figure 1: Colonoscopy Diagram

Using the guideline decision tree, what should be the patient’s follow-up?

  • 7-year colonoscopy
  • 3-year colonoscopy
  • 1-year colonoscopy
  • 6-month colonoscopy

The correct answer is ...

3-year colonoscopy.

As you follow the diagram, you will be led on a path to adenoma type. If you look at the report above, all polyps were removed via loop excision without piecemeal noting. Next, you note that one of the polyps was noted to be tubulovillous, so you progress down. Then you note that there were not greater than 10 polyps on exam, so branch out to the right and you arrive at 3-year follow-up colonoscopy.1 

Another item to note is the documentation of partial polyps and fragmentation of the polyps, which are important in the reporting and patient outcomes. In addition, decision trees similar to the one presented in this case are immensely powerful tools in medicine. They distill knowledge into an easy-to-view format that even non-medical patients can follow. They have been utilized in publications of guidelines for years. They can also be distilled for informaticians, analysts, and engineers into clinical decision support logic for use in an EMR very easily by supplementing the branches into "if/else" logic functions. Some software has even utilized this format for knowledge, automation, and treatment recommendation (Epic and Trisotec).2,3,4


  1. Gupta S, Lieberman D, Anderson JC, et al. Recommendations for follow-up after colonoscopy and polypectomy: a consensus update by the US Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2020 Mar;91(3):463-485.e5. doi:10.1016/j.gie.2020.01.014
  2. Greenes, R. A. (Ed.). (2014). Clinical decision support: the road to broad adoption. Academic Press.
  3. Epic. (n.d.). Retrieved April 15, 2022, from https://www.epic.com/about
  4. Trisotech. (2022, April 11). Retrieved April 15, 2022, from https://www.trisotech.com/

Jason Greenwood, M.D., M.S.

Fellow, Clinical Informatics
Mayo Clinic Scholar
Mayo Clinic

Justin Juskewitch, M.D., Ph.D.

Senior Associate Consultant, Transfusion Medicine
Mayo Clinic
Assistant Professor of Laboratory Medicine and Pathology
Mayo Clinic College of Medicine and Science

MCL Education

This post was developed by our Education and Technical Publications Team.