Synopsis
Recognise small-bowel obstruction and strangulation, resuscitate while defining cause and transition on contrast CT, and select non-operative management only when a safe monitored adhesional pathway is appropriate with immediate senior surgical, radiology and local contrast-protocol input.
- Small-bowel obstruction presents with colicky pain, vomiting, distension and obstipation, but diarrhoea or stool passage can continue early or in partial obstruction.
- Adhesions are common after surgery, but always examine hernial orifices and consider tumour, Crohn's stricture, volvulus, intussusception, gallstone ileus and radiation disease.
- Continuous pain, fever, tachycardia, peritonism, acidosis or CT reduced enhancement, closed loop, mesenteric oedema, pneumatosis or free fluid raises strangulation and requires urgent operation.
- A normal lactate does not exclude early ischaemia, and a raised lactate may result from dehydration; serial physiology and contrast CT matter.
- Initial care is nil by mouth, intravenous access and balanced crystalloid, electrolyte and renal correction, analgesia, antiemetic, nasogastric decompression when indicated and early surgical review.
- Contrast-enhanced CT usually confirms the transition point, cause, closed loop and bowel viability; a plain radiograph cannot safely answer all of these.
- Selected uncomplicated adhesive obstruction can undergo a closely monitored non-operative trial; hernia, malignancy, closed loop or ischaemia follows a different pathway.
- Water-soluble oral contrast can predict resolution and may be therapeutic in selected adhesional obstruction, but aspiration and hyperosmolar fluid-shift risks require a local protocol.
Key red flags
Pain becomes continuous, localised or disproportionate, with tachycardia, fever, guarding, acidosis, shock or free air. This requires immediate senior surgical and theatre planning.
Rapid severe pain and CT C- or U-shaped loop with two transition points, radial mesenteric vessels or swirl has high ischaemia risk even before peritonism.
A tender irreducible groin, incisional, parastomal or umbilical lump with obstruction is a source-control emergency; avoid forceful reduction when strangulation is plausible.
Early profuse vomiting with little distension can cause severe chloride, potassium and volume loss; aspiration risk and metabolic alkalosis may dominate.
Investigation priorities
Confirm mechanical obstruction, level and cause, identify closed loop, hernia, tumour, inflammatory disease and signs of ischaemia or perforation.
Management branches
A mechanical small-bowel obstruction is clinically suspected.
- Use ABCDE, provide analgesia and antiemetic, keep nil by mouth, gain intravenous access and correct fluid and electrolyte loss with urine monitoring.
- Place a nasogastric tube for significant vomiting, proximal dilatation or aspiration risk according to the surgical plan, confirming position before use.
- Examine hernias and stomas, send bloods and request contrast CT with an explicit obstruction and ischaemia question.
- Involve the senior surgical team from the outset and prescribe VTE prevention and antibiotics only when indicated.