Small + Large Bowel Obstruction Flashcards
1
Q
What causes small bowel obstruction
A
- Post-op adhesions (60%)
- Hernias (int + ext)
- Intussusception - part of bowel invaginates
- Malignancy
- Gallstone ileus
- TB
- Foreign body (smuggled cocaine)
- Diverticular stricture
- Constipation
2
Q
What are the different types of BO
A
- Simple = 1 obstructing point + no vascular compromise
- Closed-loop = 2 obstructing points (e.g. sigmoid volvulus) - loop grossly distended bowel at risk of perforation
- Strangulation - blood supply compromised - sharper, more constant pain + localised
3
Q
What are the symptoms of BO
A
- Vomiting occurs earlier, distension less + pain higher in abdo
- N + V (w. relief) - sometimes faecal (colonic fistula w/ proximal gut)
- Anorexia
- Colicky/ crampy pain (early)
- Distension
- Constipation (not absolute if high obstruction)
- Bowel strangulated = Pt ++ ill, ++ pain, fever peritonism
4
Q
What are the signs of BO
A
- Tinkling bowel sounds
5
Q
What are the DDx
A
- Ileus (functional obstruction due to reduced bowel motility)
- -> no mech obstruction –> bowel sounds ABSENT + no pain
6
Q
What does an AXR look like in small bowel obstruction
A
- vallvilae conniventes completely cross lumen (mucosal folds)
- central gas shadows
- no gas in L bowel
- coil-like
7
Q
How do you treat BO
A
- Depends on site + completeness of obstruction
- if paralytic ileus + incomplete SBO = manage conservatively –> NGT feeding, IV fluids
- Strangulation = emergency surgery + IV fluid
- Large bowel obstruction = emergency surgery
- -> IV fluid + enema to clear obstruction + correct fluid imbalance
8
Q
What causes large bowel obstruction
A
- Tumour
- Impacted faeces
- Diverticulitis
- Sigmoid + caecal volvulus
9
Q
What does the AXR show in large bowel obstruction
A
- peripheral gas shadows proximal to blockage (e.g. caecum) but not in rectum (unless PR performed)
- LB haustra do not cross lumen’s width
