1 DOI: https://doi.org/10.47391/JPMA.3456 1 2 Primary defect of ileal mesentery presenting as internal herniation and 3 strangulation of the small bowel: Case Report 4 5 Marya Saleem, Haris Janjua, Muhammad Zeeshan Sarwar, Syed Asghar Naqi 6 Department of Surgery, Mayo Hospital, Lahore, Pakistan. 7 Correspondence: Marya Saleem. Email: doctormariasaleem@gmail.com 8 9 Abstract 10 Primary internal hernia is a rare entity of acute intestinal obstruction. Delay in diagnosis 11 and surgical intervention can cause ischaemia or gangrene of the small bowel and result 12 in high morbidity and mortality. A 14-year-old boy presented to the emergency 13 department with acute intestinal obstruction. On exploration, 3-4cm mesenteric defect 14 was noted in the ileal region. Strangulated loops of the small bowel had gone through 15 the mesenteric defect in a complicated way. Primary anastomosis was done after 16 resection of the gangrenous small bowel. 17 Key words: Primary internal hernia, Acute intestinal obstruction. 18 19 Introduction 20 Internal herniation leading to small bowel obstruction is a well-documented entity in 21 paediatric surgery, ranging from 0.5% to 4.1%. 1 Internal herniation is either congenital 22 or acquired; the latter being in majority. Congenital or primary internal herniation 23 results from normal apertures such as foramen of Winslow or abnormal apertures arising 24 from anomalies of internal rotation and peritoneal attachment. Preoperative diagnosis in 25 emergency settings is difficult because of the rarity of the condition and non-specific 26 abdominal symptoms. 2 Delay in decision making can result in bowel ischaemia and 27 Provisionally Accepted for Publication