- Symptoms are more gradual in onset
- There are often loud borborygmi (normal bowel sounds)
- Rectum is usually empty, and the abdomen is non-tender
- Pain is lower down in the abdomen
- There may be greater distension than with small bowel obstruction
- Colon cancer
- Benign strictures – e.g. diverticular disease, IBD, ischaemic bowel, radiation damage
- Sigmoid volvulus
- Herniae – not as common as in small bowel obstruction
- Psuedo-obstruction (same as paralytic ileus, except it affects the large bowel)
- Abdominal distension and absolute constipation
- Vomiting – a very late sign
- Patient may have history of history of change in bowel habit and / or rectal bleeding
- Ask about family history – IBD and colon cancer
Closed loop obstruction
Incompetent IC valve
- The obstruction causes the small bowel to distend, and may induce vomiting
- Not as urgent as closed loop obstruction, because perforation isn’t as bigger risk
- Can be safely imaged with barium enema / endoscopy
- Can be used in palliative care where surgery isn’t appropriate
- Can also be used to buy time – ‘bridge to surgery’. The stent may allow the patient to recover enough to be fit enough for an operation.
- Usually, it is colonic cancer that is stented.
- Apple core stricture – a sign of colon cancer – is a sign on barium enema,where the lumen of the bowel looks a bit like an apple core due to the cancer causing a stricture.
- Similar pathogenesis to paralytic ileus
- You cant exclude mechanical obstruction without colonic imaging.
- Mostly the same causes as paralytic ileus, but can be affected by drug use (e.g. anti-depressants), neurological disease and pneumonia.