Appendicitis can occur after a patient undergoes a colonoscopy,¹ but because both are common, it is unclear whether a colonoscopy increases appendicitis risk. We hypothesized that patients develop appendicitis more frequently within 1 week after undergoing a colonoscopy than during the following 51 weeks.

After obtaining approval and a waiver of informed consent from the University of North Dakota and Fargo Veterans Affairs Medical Center institutional review boards, we identified 392 485 veterans from US Department of Veterans Affairs administrative data with a screening colonoscopy Current Procedural Terminology (CPT) code between January 2009 and June 2014, excluding sigmoidoscopy or incomplete colonoscopy codes. We sought over the following year a 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. We calculated the incidence rate ratio (IRR) for appendicitis within 1 week after undergoing a colonoscopy and for the following 51 weeks. χ² Statistics and 95% confidence intervals were calculated.

病人在接受结肠镜检查后会发生阑尾炎[ ^1]，但由于两者都很常见，因此尚不清楚结肠镜检查是否会增加阑尾炎的风险。我们假设患者在进行结肠镜检查后1周内比在接下来的51周内更容易发生阑尾炎。

获得批准和知情同意的从北达科他州和法戈退伍军人医疗中心伦理审查委员会的大学放弃之后，我们确定了从美国退伍军人事务部的管理数据392名485退伍军人与结肠镜筛查当前操作术语（CPT）之间的代码2009年1月和2014年6月，不包括乙状结肠镜检查或不完整的结肠镜检查代码。我们在接下来的一年寻求了阑尾切除术的CPT编码，国际疾病分类，阑尾炎的第九次修订版（ICD-9）编码，CPT和ICD-9编码或阑尾切除术CPT编码为阑尾炎的出院诊断。我们计算了结肠镜检查后1周内以及接下来的51周内阑尾炎的发生率（IRR）。χ ^2个统计和95个％置信区间的计算。