Background: Intestinal obstruction in children is a very common cause of admission in hospitals with usually a high mortality andmorbidity rate. There is a geographical variability in patterns of intestinal obstruction in pediatric population around the globe.Objectives: To evaluate patterns of presentation and surgical outcome of pediatric intestinal obstruction in Pakistan.Material and Methods: A prospective observational study with non-probability sampling technique was done in the departmentPediatric Surgery (East Surgical Unit), The Children's Hospital, Pakistan Institute of Medical Sciences (PIMS), Islamabad,Pakistan, from January to December 2017. Operated cases of intestinal obstruction from 1 day to 12 years were included. Age,patterns of presentation, sign and symptoms, surgical intervention, complications, outcome and correlation between variableswere studied.Results: Total cases were 316 (231 males, 85 females). Congenital Causes of intestinal obstruction in descending order wereAnorectal Malformations(75),Jejuno-Ileal Atresia(28), Hirschsprung Disease(27), Meckel's Diverticulum(17), DuodenalAtresia(16), Malrotation(12), Meconium Ileus(11), Midgut Volvulus(8), Mesenteric cyst(1) and Rectal Atresia(1).Acquired causeswere Intussusception(40), Perforated Appendix(20), Infantile Hypertrophic Pyloric Stenosis(14), Band Obstruction(12), BluntAbdominal Trauma(10), Obstructed Inguinal hernia (9), Worm infestation(9), Enteric Perforation(3), Necrotizing Enterocolitis(3).The overall mortality rate was 3.5% and postoperative complications rate was 40.8%. Statistically significant relationship wasfound between Age and post operative complications (P=0.048), Age and outcome (P=0.002) and between post operativecomplications and outcome (p<0.001).Conclusions: Causes of intestinal obstruction vary according to the age and geographical area. Accurate and timely diagnosis ofthe cause of intestinal obstruction along with prevention and treatment of sepsis can reduce morbidity and mortality.Key words: Intestinal obstruction; Children; Congenital; Acquired Causes; Neonate; Pakistan

Objective: To compare frequency of anastomotic leak with ligation versus preservation of azygos vein in the primary repair of esophageal atresia (EA) with trachea-esophageal fistula (TEF) in neonates. Study Design: Randomized Controlled Trial. Setting: Department of Pediatric Surgery, Pakistan Institute of Medical Sciences, Islamabad. Period: October 2019 to September 2020. Material & Methods: This study involved 180 neonates (1-28 days of life) of both genders undergoing primary repair of EA with TEF and dividied in azygous vein ligation surgery and azygous vein preservation surgery. Outcome variable was frequency of post-operative anastomotic leak. Results: In a total of 180 neonates, mean age was 6.75±6.39 days. Majority (n=130, 72.2%) of the patients were aged ≤7 days. There were 107 (59.4%) male and 73 (40.6%) female neonates. The frequency of anastomotic leak was significantly lower in Azygous vein preservation group (6.7% vs. 20.0%; p=0.009) as compared to azygous vein ligation group. Conclusion: Preservation of azygous vein was associated with significantly lower frequency of post-operative anastomotic leak among neonates undergoing primary repair of EA with TEF.