From the Guidelines
Small bowel obstruction (SBO) occurs when there is a blockage in the small intestine that prevents the normal flow of digestive contents, commonly due to adhesions, which are bands of scar tissue that form after abdominal surgery, as reported in the most recent study 1. I would explain to a patient that SBO can happen due to various reasons, including:
- Adhesions, which are bands of scar tissue that form after abdominal surgery, accounting for approximately 70% of all cases, as stated in the study 1
- Hernias, where part of the intestine pushes through a weak spot in the abdominal wall
- Tumors that grow and block the intestinal passage
- Inflammatory bowel conditions that cause swelling
- Foreign objects or gallstones that get stuck in the intestine When a blockage occurs, food, fluid, and gas cannot pass through normally, leading to symptoms like:
- Severe abdominal pain
- Vomiting
- Bloating
- Constipation
- Inability to pass gas The blockage can be partial or complete, with complete blockages being more serious as they can lead to decreased blood flow to the intestine, potentially causing tissue death if not treated promptly, as highlighted in the study 1. Treatment depends on the severity but may include bowel rest (not eating), IV fluids, nasogastric tube placement to decompress the stomach, and sometimes surgery if the obstruction doesn't resolve or if complications develop, as recommended in the most recent position paper 1. It's essential to note that the management of SBO in patients with a virgin abdomen (SBO-VA) is largely comparable to the results in patients with SBO after previous abdominal surgery, and therefore, patients with a virgin abdomen could be treated according to existing guidelines for SBO and adhesive small bowel obstruction, as proposed in the study 1.
From the Research
What is Small Bowel Obstruction (SBO)
- Small bowel obstruction (SBO) is a commonly diagnosed disease in the emergency department (ED) 2
- SBO is most commonly due to occlusion of the small intestine, resulting in fluid and gas accumulation, which may progress to mucosal ischemia, necrosis, and perforation 2
- A variety of etiologies are present, but in adults, adhesions are the most common cause 2, 3
Causes and Classification of SBO
- Several classification systems are present, but the most important distinction is complete vs. partial and complicated vs. simple obstruction, as complete complicated SBO more commonly requires surgical intervention 2
- Adhesive small bowel obstruction (ASBO) can be managed non-operatively in 70-90% of patients 3
- A patient with a history of abdominopelvic surgery along with one or more cardinal features of obstruction should be suspected to have ASBO until proven otherwise 3
Diagnosis of SBO
- History and physical examination can vary, but the most reliable findings include prior abdominal surgery, history of constipation, abdominal distension, and abnormal bowel sounds 2, 4
- Signs of strangulation include fever, hypotension, diffuse abdominal pain, peritonitis, and several others 2
- Diagnosis typically requires imaging, and though plain radiographs are often ordered, they cannot exclude the diagnosis 2, 3
- Computed tomography (CT) and ultrasound are reliable diagnostic methods 2, 4, 3
- CT has higher sensitivity and specificity compared to plain films and is recommended by the Bologna guidelines 3
Management of SBO
- Management includes intravenous fluid resuscitation, analgesia, and determining need for operative vs. nonoperative therapy 2
- Nasogastric tube is useful for patients with significant distension and vomiting by removing contents proximal to the site of obstruction 2, 5
- Surgery is needed for strangulation and those that fail nonoperative therapy 2, 3, 5
- Laparoscopic adhesiolysis is recommended with advances in minimal access technology and increasing experience 3
- Mechanical adhesion barriers are an effective measure to prevent adhesion formation 3