• KEY POINTS① Suspected SBO is best evaluated using abdomen CT with IV contrast only.② Identifying transition point is the key to determining the cause of the obstruction.③ When evaluating the obstruction cause(intrinsic, extrinsic, or intraluminal), the most common cause of SBO is intra-abdominal adhesions.④ The presence or absence of a closed-loop obstruction, which should be mentioned by CT.⑤ Reduced bowel wall enhancement and mesenteric edema are the most specific and sensitive, respectively, signs of bowel ischemia, a surgical emergency.