S3788 Proctitis by Peroxide: Chemical Colitis Following an At-Home Enema

Introduction: Constipation is a common disorder that can be managed with a variety of enemas, including prescriptions, over the counter, and homemade formulations. These enemas have varying degrees of safety with adverse effects including electrolyte abnormalities and chemical mucosal injury. This case presents a woman who presented with hematochezia and abdominal pain after a hydrogen peroxide enema. Case Description/Methods: A 37-year-old woman with history of constipation presented with abdominal pain and hematochezia. Earlier that day, she had self-administered a mixed hydrogen peroxide and water enema after reading about it online. The enema began creating bowel movements but then caused progressive abdominal pain and small volume hematochezia. Her abdominal exam was benign without tenderness or peritoneal signs. Initial laboratory workup revealed leukocytosis but otherwise was normal. Computed tomography of her abdomen and pelvis with intravenous contrast showed rectal wall thickening and possible pneumatosis as well as possible trace portal venous gas. Flexible sigmoidoscopy found shallow circumferential ulcers from anorectal junction to 13 cm proximal with normal tissue more proximal to this. Biopsies showed acute ischemic injury. Her pain and hematochezia improved, and she was discharged the next day with plans for a follow-up colonoscopy to assess healing and for potential stricturing. Discussion: Hydrogen peroxide is an oxidizing agent that had been used in the early 20th century for meconium ileus due to its prokinetic effects. Its use fell out of favor after reports began to circulate of chemical injury after administration. There are still documented cases of use of hydrogen peroxide enemas, often promoted by unvalidated internet sources such as TikTok. Patients usually present with similar findings to our patient with abdominal pain and hematochezia with similar findings of proctitis on imaging and endoscopy. Gastroenterologists must be aware of emerging trends, counsel patients on evidence-based treatments, and actively combat misinformation online. Conservative management usually results in a full recovery.