Large Bowel Obstruction Flashcards
What are the main causes of large bowel obstruction?
Malignancy (90% of all)
Volvulus
Intussusception (telescoping)
Diverticular disease
What is intussusception?
One part of intestine slides into an adjacent part (telescopically), blocks food passing through and cuts blood supply to affected part of intestine
Most common in children under 3
What is a volvulus?
A loop of intestine loops around itself and the mesentery that supplies it causing bowel obstruction
What is a competent ileocaecal valve?
The valve between the ileum and caecum (first part of colon) only allows movement forwards into colon not back
What is a closed-loop obstruction?
2 points of obstruction along the bowel so the middle section cannot drain or decompress
Commonly involves a competent ileo-caecal valve
What are possible causes of a closed-loop obstruction?
Adhesions that compress 2 areas of bowel
hernias that isolate a section and block either side
Single point of obstruction (eg tumour) with a competent ileocecal valve
What happens within a closed-loop obstruction?
The contents can’t drain or decompress so expand (particularly if competent ileocecal valve involved)
Leads to ischaemia and perforation.
Requires emergency surgery
What are symptoms of large bowel obstruction?
Constipation then vomiting (green bilious vomit)
Abdominal distension
Diffuse abdominal pain
Lack of flatulence
Hyperactive then normal then absent bowel sounds
How is a large bowel obstruction diagnosed?
1st line = Xray
Shows dilated bowel loops and transluminal fluid-gas shadows
If sigmoid volvulus then will show coffee bean sign
Gold standard= abdominal CT
How is a large bowel obstruction treated?
Fluid replacement (drip)
NG tube (drain)
Antiemetic and analgesia
Antibiotics as high infection risk
Surgery is last resort
