Bowel obstruction is the interference with movement of bowel content. Large and small in testing from duodenum to anal region can be obstructed mechanical or non-mechanical and complete or partial. Mechanical obstruction can presented because of obstructive causes in intestinal lumen, intestinal wall or pressure from other tissue on intestine.The aim of the study was to evaluate etiology, laboratory findings of intestinal obstruction and ileus among children and adults who discharged with good condition.Material and methods. This retrospective study was carried out from 2001 to 2006 in Imam Khomeini Hospital (Ahvaz-Iran). Cases of bowel obstruction were included in this study. For each case, a questionnaire was filled. There are 752 cases with suspected bowel obstruction. From 752 cases, 403 patients that agreed and treated and discharged with good condition were studied. Cases were divided into two groups: children (age < 15 yrs) and adults (age> 15 yrs). Data were analyzed by SPSS Ver 16.0 (Chicago, IL, USA) and Epi-info Ver 6.00.Results. In our study, 221 adults and 192 children were included. Mortality rate was 12.2%. Forty-eight percent of 403 cases were children (m - 61%, f - 38%, ambigus genitalia - 1%) and 52% were adults (m - 67%, f - 33%). Etiology of bowel obstruction in children were as follows: ileus (26%); adhesion band (17.7%), partial obstruction (16.1%), and Hirschsprung's disease (12%). Causes of bowel obstruction in adults are: partial obstruction (29.9%); ileus (19%); adhesion band (18.5%); colonic pseudo obstruction(8.5%); GI cancer (5.2%); hernia (4.7%); Crohn (2.8%); fecal impaction (3.3%); bezoar (2.4%), and 4.7% for other causes. Fifty-one percent of children and 36% of adults were operated. Of all children, 91.7% had upright abdominal X-ray, 51.6% had supine X-ray, and 80.7% had sonography. Hundred percents of adults had upright & supine plain abdominal X-ray and 75.4% had sonography. Most change in children's CBC was 10000<WBC<15000 and in adult for WBC<10000.Conclusions. Partial obstruction, pseudo-obstruction, and cancer were more common in adults than children. Ileus was the commonest cause of obstruction in children and it was partial obstruction for adult. Children were more operated than adult. Sonography was more use for children but plain abdominal X-ray for adult. In 45% of children 10000<WBC<15000 while most adult had WBC<10000. Hypokalemia was the most common biochemical finding in both group.