Mesenteric cyst is a rare cause of abdominal mass and is difficult to diagnose because of the lack of characteristic clinical findings and the nonspecific radiological follow-up methods. The initial manifestation is usually abdominal distension in uncomplicated cases.A 1.5-year-old male patient was admitted to our clinic with complaints of abdominal pain that had started two days earlier together with ongoing bilious vomiting for the last two days. On physical examination, multiple cavities with definite airfluid levels were seen but no gas was present in the distal bowel despite the abdominal distension. Surgery verified the presence of a large 10x10 cm mesenteric cyst torsion and an accompanying Meckel’s diverticulum, The ischemic bowel loop at this area was resected and an end-to-end anastomosis performed for the ileal segments. The case was able to tolerate oral feeding on the 4th post-operative day and was discharged with no complaints on the sixth day.It is difficult to distinguish uncomplicated mesenteric cysts from normal intestines on USG. Mesenteric cysts should be considered in differential diagnosis in patients admitted with complaints of abdominal distension where the reason for the increased intra-abdominal fluid is unknown. USG and tomography can be helpful in the follow-up. Additional abnormalities should also be taken into account, and surgical excision is sufficient for treatment

Keywords: Children, Ileus, Mesenteric cysts, Torsion