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.