 Introduction/Background Small-bowel obstruction (SBO) is responsible for up to 16% of hospital admissions for abdominal pain with mortality ranging between 2% to 8% overall, and as high as 25% when associated with bowel ischemia [1,2]. Radiologic imaging plays the key role in the diagnosis and management of SBO because neither patient presentation, the clinical examination, nor laboratory testing are sufficiently sensitive or specific enough to diagnose or guide management [2-8]. Imaging not only diagnoses the presence of SBO but also can aid in the differentiation of high-grade from low-grade obstruction. This differentiation helps to guide referring physicians between surgical treatment for high-grade or complicated SBO versus conservative management with enteric tube decompression. Imaging also serves to localize the site of obstruction and evaluate possible causes of obstruction with the most common cause being adhesions, accounting for 70% of all cases. Other causes include hernias, malignancies, Crohn disease, intussusception, volvulus, gallstone ileus, obstructive foreign bodies and bezoars, trauma, endometriosis, and iatrogenic causes. Finally, imaging can play a role in the detection of related findings that may prompt surgical treatment such as ischemia, internal hernia, or volvulus [2-8]. This document refers to imaging appropriateness in diagnosis of adult patients, >18 years of age. Discussion of Procedures by Variant Variant 1: Suspected small-bowel obstruction. Acute presentation. Initial imaging. The typical acute presentation of a patient suspected of having SBO includes intermittent crampy central abdominal pain, distension, nausea, and vomiting. Physical examination findings include abdominal distension with either absent or high-pitched bowel sounds. Abnormal laboratory findings such as an elevated white blood cell count, elevated lactic acid, or elevated serum amylase raise the suspicion for a complication such as ischemia.
Suspected Small Bowel Obstruction.  Introduction/Background Small-bowel obstruction (SBO) is responsible for up to 16% of hospital admissions for abdominal pain with mortality ranging between 2% to 8% overall, and as high as 25% when associated with bowel ischemia [1,2]. Radiologic imaging plays the key role in the diagnosis and management of SBO because neither patient presentation, the clinical examination, nor laboratory testing are sufficiently sensitive or specific enough to diagnose or guide management [2-8]. Imaging not only diagnoses the presence of SBO but also can aid in the differentiation of high-grade from low-grade obstruction. This differentiation helps to guide referring physicians between surgical treatment for high-grade or complicated SBO versus conservative management with enteric tube decompression. Imaging also serves to localize the site of obstruction and evaluate possible causes of obstruction with the most common cause being adhesions, accounting for 70% of all cases. Other causes include hernias, malignancies, Crohn disease, intussusception, volvulus, gallstone ileus, obstructive foreign bodies and bezoars, trauma, endometriosis, and iatrogenic causes. Finally, imaging can play a role in the detection of related findings that may prompt surgical treatment such as ischemia, internal hernia, or volvulus [2-8]. This document refers to imaging appropriateness in diagnosis of adult patients, >18 years of age. Discussion of Procedures by Variant Variant 1: Suspected small-bowel obstruction. Acute presentation. Initial imaging. The typical acute presentation of a patient suspected of having SBO includes intermittent crampy central abdominal pain, distension, nausea, and vomiting. Physical examination findings include abdominal distension with either absent or high-pitched bowel sounds. Abnormal laboratory findings such as an elevated white blood cell count, elevated lactic acid, or elevated serum amylase raise the suspicion for a complication such as ischemia.