What criteria should I use to determine when to refer a patient with small bowel obstruction for surgical evaluation?

Criteria for referral of a patient with small bowel obstruction for surgical evaluation include:

• Signs of complicated obstruction: absolute constipation (no passage of flatus or stool), persistent vomiting, and abdominal distension suggest intestinal obstruction requiring urgent assessment and possible surgery NICE NG147.
• Clinical features indicating complications: uncontrolled abdominal pain, abdominal rigidity or guarding (suggesting perforation or peritonitis), palpable abdominal mass (possible abscess), or signs of sepsis such as altered mental state, low blood pressure, tachycardia, and reduced urine output warrant same-day hospital referral NICE NG147.
• Failure to improve or worsening symptoms: patients with persistent or worsening symptoms despite initial management in primary care should be referred for secondary care assessment NICE NG147.
• Raised inflammatory markers: if inflammatory markers are elevated, urgent imaging (contrast CT if possible) is indicated to confirm diagnosis and guide management, supporting the need for surgical evaluation if complicated obstruction is confirmed NICE NG147.

In summary, refer patients with small bowel obstruction for surgical evaluation if they have absolute constipation, vomiting, abdominal distension, signs of peritonitis or sepsis, or if symptoms persist or worsen despite initial management NICE NG147.