Supplementary Material for: A Novel Case of Ischemic Colitis in the Setting of Kratom Use: A Case Report

Introduction:
Kratom is an herbal preparation made from leaves of a tree (Mitragyna speciosa) indigenous to Southeast Asia. Its physiological effects are mainly potentiated by mitragynine, a partial mu-opioid receptor agonist, and they are dose-dependent: low doses mimic stimulants, while higher doses have sedative and analgesic effects. There are no approved medical indications for kratom use, but several mice studies and a cross-sectional study in humans have demonstrated that kratom use can significantly decrease withdrawal symptoms among opioid users. Although injury and failure of various organs have been reported with kratom use across multiple case study analyses, gastrointestinal involvement has been rarely documented.

Case Presentation:
We present a 26-year-old female with no past medical history, no risk factors for intestinal ischemia, and an addiction to the commercial substance, kratom, who presented for one day of bright-red bloody diarrhea and bilious vomiting, and several weeks of intermittent sharp abdominal pain. Colonoscopy showed decreased mucosa vascular pattern in watershed areas of the colon and a splenic flexure that was so ulcerated it could not be safely traversed.

Conclusion:
Given the lack of concomitant risk factors and comorbidities, as well as the timing of her symptoms, our patient most likely developed ischemic colitis due to her kratom use. This is further supported by her repeat colonoscopy two months after quitting kratom, which showed complete resolution. We would advise vigilance for possible bowel ischemia in those using kratom, a substance on which there is currently limited knowledge.

引言：
卡痛叶（Kratom）是一种由原产于东南亚的帽柱木（Mitragyna speciosa）叶片制成的草本制剂。其生理效应主要由帽柱木碱（mitragynine）介导，该物质属于部分μ阿片受体激动剂，且效应呈剂量依赖性：低剂量下可模拟兴奋剂作用，高剂量则产生镇静与镇痛效果。目前尚无获批的卡痛叶临床用药适应症，但多项小鼠实验与一项人类横断面研究表明，使用卡痛叶可显著缓解阿片类药物使用者的戒断症状。尽管多项病例分析报告显示使用卡痛叶可引发多器官损伤与功能衰竭，但胃肠道受累的相关记录却极为罕见。

病例报告：
本文报告1例26岁女性患者，既往无病史，无肠缺血危险因素，但存在商用卡痛叶成瘾史。患者因1天的鲜红色血便、胆汁性呕吐，以及持续数周的间歇性剧烈腹痛就诊。结肠镜检查显示结肠分水岭区域黏膜血管纹理减少，脾曲溃疡严重，无法安全通过内镜。

结论：
鉴于患者无合并危险因素与基础疾病，结合症状发作时间，该患者的缺血性结肠炎极有可能由使用卡痛叶所致。患者停用卡痛叶2个月后复查结肠镜显示病变完全消退，进一步印证了这一推论。鉴于目前对卡痛叶的认知仍较为有限，我们建议对使用卡痛叶的人群保持警惕，警惕其可能引发的肠缺血。