Paralytic Ileus

Paralytic ileus is failure of coordinated intestinal propulsion without a mechanical transition point.

It commonly follows abdominal surgery but also occurs with peritonitis, sepsis, pancreatitis, retroperitoneal pathology, electrolyte disturbance, severe systemic illness and drugs, particularly opioids and anticholinergic agents.

Unlike mechanical obstruction, the bowel is functionally inactive rather than physically blocked.

Abdominal distension, nausea, vomiting and failure to pass stool or flatus are typical.

Pain is usually dull and diffuse rather than severe colic. Marked colicky pain should prompt reconsideration of mechanical obstruction.

The abdomen is distended with reduced bowel sounds, although bowel sound character alone cannot reliably distinguish ileus from obstruction.

Postoperative ileus that persists longer than expected should trigger evaluation for anastomotic leak, intra abdominal abscess, electrolyte disturbance, opioid excess or mechanical obstruction rather than being labelled simply prolonged postoperative ileus.

Check electrolytes, particularly potassium and magnesium, renal function and inflammatory markers when infection is possible.

CT abdomen and pelvis with IV contrast: use when mechanical obstruction or an intra abdominal complication must be excluded; ileus shows diffuse bowel dilatation without a discrete mechanical transition point.

Treat the precipitating cause.

Correct potassium, magnesium and volume deficits. Stop or reduce opioids, anticholinergics and other motility suppressing drugs where possible.

Use multimodal opioid sparing analgesia, mobilise early and avoid unnecessary fluid overload. ERAS guidance supports early mobilisation, optimised fluids, opioid reduction and early enteral intake as central measures for preventing and treating postoperative gastrointestinal dysfunction.

Nasogastric decompression is selective rather than routine. Use it for persistent vomiting, major gastric distension or aspiration risk, and remove it once decompression is no longer needed.

Do not keep every patient fasting until bowel sounds or flatus return. Early oral or enteral nutrition should be reintroduced as tolerated once vomiting and severe distension settle.

Routine metoclopramide or erythromycin does not reliably reverse postoperative ileus.

Persistent or worsening ileus accompanied by fever, tachycardia, focal tenderness or rising inflammatory markers requires investigation for a surgical complication rather than continued supportive treatment alone.