Appendectomy as a Risk Factor for Lymphocytic Colitis

Introduction: Microscopic colitis (MC) is a family of chronic inflammatory bowel diseases (IBD), including lymphocytic colitis (LC) and collagenous colitis (CC).1 While frequently having normal endoscopic appearance, both LC and CC have specific histopathology.1 The pathogenesis of MC is considered to be multifactorial.1 The triggers for MC include infections, drugs, autoimmunity, and bile acids.1 Little is known about inflammatory mediators in MC, but it has been noted to be predominantly T-lymphocytic. There is an ongoing controversy regarding appendectomy being a risk factor for MC. We are going to present a case of LC post-appendectomy. Case Description/Methods: A 52-year-old female developed diarrhea 8 weeks post-appendectomy. Before surgery, patient was struggling with constipation. Patient is having diarrhea 5 times a day with no blood or mucus in stool, no food triggers. Patient’s only long-term medication is diazepam. No ibuprofen use reported. She drinks alcohol occasionally and is a 1-pack-per-day smoker. Patient had 2 CT scans, ultrasound of the abdomen, stool studies, Clostridium difficile and celiac panel done – all of them unrevealing. Biopsy showed lymphocytic colitis. Patient improved on budesonide after failing loperamide. Discussion: The appendix has long been considered a vestigial organ. In recent years, however, reports have suggested that it could be linked to numerous immunological functions.2 One theory suggests that appendix may serve as a reservoir from which the gut flora can be rapidly re-established.2 The other theory suggest that appendix may play a role in development of IBD. Several studies demonstrated that appendectomy could lower the risk of ulcerative colitis (UC) when done before developing UC.2 Appendectomy in patients with established UC, however, appears to be associated with a worse disease course.2 Similarly, we wonder if our case could be establishing a link between appendectomy and MC. Like there is exaggerated inflammatory response post-appendectomy in patients with known UC, appendectomy could be a trigger for lymphocytic infiltration which results in LC.Figure 1.: Microscopic colitis on histopathology.