BACKGROUND@#
Cholecystectomy is a standard
surgery for
patients suffering from
gallbladder diseases, while the causal effects of
cholecystectomy on
colorectal cancer (CRC) and other
complications are still unknown.@*
METHODS@#We obtained genetic variants associated with
cholecystectomy at a
genome-wide significant level ( P value <5 × 10 -8 ) as instrumental variables (IVs) and performed Mendelian
randomization (MR) to identify the
complications of
cholecystectomy. Furthermore, the
cholelithiasis was also treated as the exposure to compare its causal effects to those of
cholecystectomy, and multivariable MR
analysis was carried out to judge whether the effect of
cholecystectomy was independent of
cholelithiasis. The study was reported based on Strengthening the
Reporting of Observational Studies in
Epidemiology Using Mendelian
Randomization guidelines.@*RESULTS@#The selected IVs explained 1.76% variance of
cholecystectomy. Our MR
analysis suggested that
cholecystectomy cannot elevate the
risk of CRC (
odds ratio [OR] =1.543, 95%
confidence interval [CI] 0.607-3.924). Also, it was not significant in either
colon or
rectum cancer. Intriguingly,
cholecystectomy might decrease the
risk of
Crohn's disease (OR = 0.078, 95% CI 0.016-0.368) and
coronary heart disease (OR = 0.352, 95% CI 0.164-0.756). However, it might increase the
risk of
irritable bowel syndrome (IBS) (OR = 7.573, 95% CI 1.096-52.318).
Cholelithiasis could increase the
risk of CRC in the largest
population (OR = 1.041, 95% CI 1.010-1.073). The multivariable MR
analysis suggested that genetic liability to
cholelithiasis could increase the
risk of CRC in the largest
population (OR = 1.061, 95% CI 1.002-1.125) after
adjustment of
cholecystectomy.@*CONCLUSIONS@#The study indicated that
cholecystectomy might not increase the
risk of CRC, but such a conclusion
needs further proving by clinical equivalence. Additionally, it might increase the
risk of IBS, which should be paid
attention to in clinical practice.