Intestinal obstruction (IO) continues to be a major problem for human being since it was first recognized and treated in 350 Before Christ. Different treatment options were developed since then with only minimal reduction in morbidty and mortality. It occurs when the normal flow of intestinal content is interrupted. Intestinal obstruction is the most common causes of emergency surgical admission through out world. It is also one of the major causes of morbidity and mortalities associated with acute abdomen. The proportion and etiologies of intestinal obstruction differ not only from country to country but also with in the different regions of the same country. Knowing proportion of obstruction is very important to manage patients accordingly. Only very few data concerning proportion of intestinal obstruction is found in Ethiopia and none in Debre Birhan. The aim of the study is to assess the proportion of intestinal obstruction and associated factors among patients with non traumatic acute abdomen admitted to surgical ward in Debre Birhan Referral Hospital from December 8,2015 to January 9,2016. Facility based cross-sectional study was conducted by using 357 patient’s record with acute abdomen from December 8,2015 to January 9,2016. Collected data was entered in to SPSS version 20. Adjusted Odds ratio with 95% confidence interval and p-value were used to measure associations. From 357 study subjects 181 (50.7%) and 141 (39.5%) were Intestinal obistruction and acute appendicitis cases respectively with response rate of 99.4%. large bowel obstruction (LBO) accounts for about 109 (60.2%) of cases while 72 (39.8%) of cases were small bowel obstruction (SBO). Male gender, residence and constipation are significantly associated with intestinal obstruction (P<0.05). From all study subjects those who had previous history of constipation were 61 (33.7%), previous history of abdominopelvic operation 25 (7%), previous history of intestinal obstruction 35 (9.8%), hernia 12 (3.4%) and previous history of rectal bleeding 5 (1.4%). Intestinal obstruction is the most common cause for non traumatic acute abdominal admission accounting 50.7%. In the study area Male gender, constipation and urban residence are significantly associated with intestinal obstruction. Postoperative adhesion and garoin hernias were found to be the commonest causes for intestinal obstruction next to Volvulus, but tumor was the rare cause of small bowel obstruction in the study area. Elective repair of hernia should be strengthened before it causes obstruction. Public awareness should be increased on the risk factors of intestinal obstruction through health education to reduce the observed magnitude. Moreover, health facilities and health professionals capable of handling patients with intestinal obstruction should be available with in the reach of the community.

Keywords: Intestinal Obstruction, Small Bowel Obstruction, Large Bowel Obstruction, Hernia