From the Guidelines
Bowel obstruction is characterized by several key symptoms including abdominal pain, abdominal distension, vomiting, and constipation or inability to pass gas, as reported in a 2019 narrative review published in the World Journal of Emergency Surgery 1. The symptoms of bowel obstruction can vary depending on the location and completeness of the obstruction.
- Abdominal pain that may be crampy and intermittent
- Abdominal distension or bloating
- Vomiting, which may become feculent in complete obstructions
- Constipation or inability to pass gas Other signs of bowel obstruction include:
- Decreased or absent bowel sounds
- Dehydration
- Rapid heart rate
- Fever in cases of strangulation The severity and combination of symptoms depend on the location and completeness of the obstruction, with small bowel obstructions typically causing more central abdominal pain and earlier vomiting, while large bowel obstructions often present with lower abdominal pain and significant distension, as noted in the study 1. These symptoms occur because the blockage prevents the normal passage of intestinal contents, causing backup and distension of the bowel proximal to the obstruction, which can compromise blood flow to the bowel wall and lead to serious complications, including bowel perforation, peritonitis, and sepsis, highlighting the importance of prompt medical attention 1.
From the Research
Signs of Bowel Obstruction
- Nausea and emesis 2
- Colicky abdominal pain 2
- Cessation of passage of flatus and stool 2
- Abdominal distension 3, 2
- Tympany to percussion 2
- High-pitched bowel sounds 2
- Abnormal bowel sounds 3
- Constipation 3
- History of abdominal surgery 3
Diagnostic Findings
- Multidetector computed tomography (MDCT) is used to diagnose bowel obstruction, focusing on four key points: confirming the obstruction, determining the transition point, establishing the cause, and seeking signs of complications 4
- Computed tomography (CT) is accurate in diagnosing small bowel obstruction, with a pooled positive likelihood ratio of 3.6 3
- Magnetic resonance imaging (MRI) is also accurate in diagnosing small bowel obstruction, with a pooled positive likelihood ratio of 6.77 3
- Ultrasound (US) has a high positive likelihood ratio of 14.1 for formal scans and 9.55 for bedside scans, making it a useful imaging modality for diagnosis 3
- Laboratory evaluation should include a complete blood count, metabolic panel, and serum lactate level 2