An incidental finding of mesenteric hematoma in a patient with a new diagnosis of inflammatory bowel disease.

Mesenteric hematomas (MHs) are relatively rare and are characterized by localized bleeding in the mesenteric vascular tree presenting with abdominal pain, vomiting, abdominal distension, masses, and hypotension. We report a case of a MH which was incidentally found in a 10-year-old patient with a new diagnosis of ulcerative colitis (UC). This is the second-ever reported case of MH associated with inflammatory bowel disease to our knowledge, with the first being in an adult female with Crohn's disease. The patient presented with painless hematochezia with unknown etiology and underwent an exploratory laparotomy when a mesenteric hematoma was incidentally found. Further investigation including a computed tomography angiopathy showed findings concerning for inflammatory bowel disease and colonoscopy with biopsy confirmed a diagnosis of UC. We propose that the MH was a result of inflammation which caused microvascular bleeding/thrombotic events. Management strategies including follow-up of resolution is not well delineated in the literature.