Influence of moon phases on bowel preparation quality in a screening colonoscopy collective

Background:

Moon phases, in particular full moon, are often discussed to have an impact on sleep and activity behavior as well as various other functions of the human body.

Aim:

The aim of the present study was to investigate the impact of moon phases on bowel preparation quality.

Methods:

We analyzed bowel preparation quality according to a modified Aronchick Score in screening colonoscopies performed between 08/2008 and 12/2018 within a national quality assurance program in Austria. Consistent with the current Guidelines of the European Society for Gastrointestinal Endoscopy (ESGE) preparation quality rated as excellent, good or fair were considered sufficient.

Results:

207,593 screening colonoscopies were included in the study. 50.74% of screenees were woman, mean age was 60.9 years (SD 9.1). Bowel preparation quality was sufficient in 95.94% of examinations. Overall bowel preparation quality differed significantly between moon phases (new/waning/waxing/full moon, p = 0.014). 3.12% (n = 6,480) of colonoscopies were performed the day after a full-moon night. Those patients had a significantly higher rate of inadequate bowel preparation as compared to other moon phases (relative risk 1.18 [95% CI 1.06 – 1.32], p = 0.004). Notably, this effect was only significant in men (5.32% vs. 4.22% insufficient preparation; p = 0.003, women p = 0.26).

Conclusion:

If screening colonoscopy is scheduled on a day after a full moon night, patients, particularly male patients, should be intensely instructed to follow bowel preparation guidelines.