(HealthDay News) — The risk of appendicitis is increased in the week following colonoscopy, according to a research letter published in the January issue of JAMA Surgery.
Marc D Basson, MD, PhD, from the University of North Dakota School of Medicine and Health Sciences in Grand Forks, and colleagues identified 392,485 veterans with a screening colonoscopy code between January 2009 and June 2014. Over the following year the authors sought a Current Procedural Terminology (CPT) code for appendectomy, an International Classification of Diseases, Ninth Revision (ICD-9) code for appendicitis, both CPT and ICD-9 codes, or the appendectomy CPT code with a discharge diagnosis of appendicitis. The incidence rate ratio (IRR) for appendicitis within one week after undergoing a colonoscopy was calculated.
The researchers found that there were more frequent codes for appendicitis or an appendectomy one week after a colonoscopy than in the following 51 weeks. This result was not affected by age subgrouping, and there was no increase in appendicitis in weeks 2 to 4. Within the cohort, there was no increase in appendectomy one week after bronchoscopy, knee replacement procedure, cataract surgery, or knee arthroscopy. The IRR was 6.8 for appendicitis within a week after colonoscopy considering only validated patients from the CPT-based strategy.
“These results suggest that undergoing a colonoscopy predisposes patients to appendicitis within one week,” the authors write. “The mechanism of this effect awaits elucidation.”
- Basson MD, Persinger D, Newman WP. Association of Colonoscopy With Risk of Appendicitis. JAMA Surg. 2018 Jan. doi:10.1001/jamasurg.2017.3790