This chapter discusses the diagnosis, evaluation and management of small bowel obstruction (SBO). It details the specific types of small bowel obstruction. Common causes of small bowel obstruction include hernias, neoplasms, intussusception, and others. Thorough history should be taken, with particular attention paid to prior SBOs, abdominal surgeries, hernias, cancer, and opiate use. The vital signs of SBO are: fever, tachycardia, hypotension, and tachypnea. The examination of the abdomen is performed by visually inspecting the abdomen for scars and distension. Rectal examination is considered with evaluation for occult blood, although diagnostic yield may below and classically the rectal vault will be empty. In laboratory evaluation findings are not specific to bowel obstruction. Results may show evidence of dehydration, acidosis, renal failure, and leukocytosis. Antibiotics are indicated with evidence of ischemia, perforation, or severe disease, although there is no good evidence supporting or refuting the use of empiric broad-spectrum antibiotics.