Synopsis
Diagnose mechanical obstruction and its complications, assess whether surgery, stent or venting can achieve meaningful benefit, and provide coordinated non-oral analgesic, antiemetic, antisecretory, corticosteroid, hydration and mouth care when medical management is chosen.
- Suspect malignant obstruction with colic or continuous pain, distension, nausea, vomiting, reduced flatus or stool and known intra-abdominal or pelvic cancer.
- First-line safety assessment looks for peritonitis, ischaemia, perforation, strangulated hernia, aspiration, sepsis, severe dehydration and renal injury.
- Contrast CT abdomen and pelvis is the gold-standard investigation for site, completeness, number of levels, complications, tumour burden and interventional planning.
- Early multidisciplinary review separates a potentially correctable single-level obstruction from multifocal carcinomatosis or functional failure unlikely to benefit from surgery.
- Surgery or stent is favoured when anatomy is correctable, performance and prognosis allow recovery, symptom benefit is meaningful and the patient accepts burden.
- Nasogastric decompression provides short-term relief from large-volume vomiting; a venting gastrostomy can support longer symptom control when intervention will not restore transit.
- In complete obstruction avoid metoclopramide, stimulant or bulk laxative and use non-prokinetic antiemetic, opioid, antisecretory medicine and a short corticosteroid trial.
- In partial obstruction without colic, a cautious metoclopramide trial may improve transit, but stop immediately if colic or vomiting worsens.
- The gold-standard plan names the branch, rescue and pump medicines, decompression, intake and hydration approach, review window and triggers for changing goal.
Key red flags
Peritonism, shock, fever, rapidly worsening continuous pain or lactate rise requires urgent surgery and sepsis assessment.
Faeculent vomiting, aspiration, severe dehydration or altered consciousness threatens airway, kidney function and medicine absorption.
Complete mechanical obstruction with colic is a contraindication to metoclopramide and stimulant or bulk laxatives.
A tense closed-loop obstruction, volvulus or incarcerated hernia can progress rapidly despite modest early imaging or examination findings.
Neutropenia, recent surgery, radiotherapy or immunotherapy broadens the differential to enterocolitis, leak, stricture and inflammatory toxicity.
Persistent high nasogastric output, oliguria, potassium disturbance or rising creatinine requires active fluid, electrolyte and renal medicine review.
Octreotide can cause glucose disturbance, bradycardia and biliary effects, while antimuscarinics can worsen retention, dry mouth and delirium.
Peritonism, shock, fever, continuous escalating pain or lactate rise suggests ischaemia, perforation or sepsis.
Investigation priorities
Assess stability, hydration, distension, focal or colicky pain, peritonism, masses, scars, hernias, bowel sounds and rectal loading.
Management branches
Obstruction symptoms accompany continuous severe pain, peritonism, instability, fever or rapid deterioration.
- Use ABCDE care, stop oral and enteral intake, obtain access and blood tests and call urgent surgical and acute oncology teams within the treatment ceiling.
- Arrange immediate CT or operative decision, give protocol antimicrobial and resuscitation care when indicated and provide non-oral analgesia and antiemetic.
- Avoid prokinetic, stimulant, bulk and rectal treatment and document the patient's capacity, intervention wishes and reassessment point.