3. CLASSIFICATION
1 –Mechanical ( dynamic) :
Bowel capable of contracting normally or
excessively proximal to a local site of obstruction.
2 – Non-Mechanical (adynamic):
Peristalsis maybe absent (paralytic ileus),
OR present in non-propelsive form (mesenteric
vascular occlusion, pseudo-obstruction).
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5. Common causes of mechanical small bowel
obstruction:
1. Adhesions and bands following abdominal surgery
2. External hernia
3. Intussusceptions
4. Volvulus
5. Neoplasm (benign or malignant).
6. Obstruction : worms
7. Stricture: IBD 5
6. Common causes of mechanical large
bowel obstruction
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1. Large bowel cancer.
2. Sigmoid diverticular disease.
3. Sigmoid volvulus.
10. Common causes of non-mechanical small-bowel
obstruction
1 – Paralytic ileus after abdominal surgery
2 – Localized intra abdominal abscess or generalized
peritonitis
3– Mesenteric embolism or thrombosis with small
bowel infarction
4 – Intestinal pseudo-obstruction
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11. Common cause of non-mechanical large
bowel obstruction:
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1 – Retroperitoneal hematoma following lumber
fracture or lumber surgery
2 – Idiopathic
16. 2 - CLOSED LOOP OBSTRUCTION
Bowel obstructed at both proximal & distal
points
There is rapid increase in the intra luminal
tension, Gangrene or perforation can occur
more quickly, peritonitis.
Example: Colonic obstruction with
competent ileocaecal valve
17. 3 – STRANGULATION
This is the end result a closed loop
obstruction when major arterial supply to the
affected bowel has been occluded , causing
gangrene over a considerable area.
18. Mechanical obstruction
Following questions must be answered:
1 – Is it obstruction and if so at what level ?
2 – Is strangulation present ?
3 – Is dehydration present ?
4 – What is the cause ?
5 - What is the treatment for the individual
case ?
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19. 1 – Is it obstruction, and if so, at what
level ?
The question is answered by considering the
clinical features.
Symptoms
Signs
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21. Pain
Sudden, severe
Colicky in nature
Central , around umbilicus in small bowel
obstruction
Lower abdomen in large bowel obstruction
Continuous if perforation or strangulation is
present
Absent in paralytic ileus.
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22. Vomiting
Early in high small bowel obstruction,
Late in low small bowel obstruction ,
Delayed or absent in large bowel obstruction.
Character : initially clear ,becomes discolored
, and finally feculent (dark and foul smiling).
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24. Distension
Epigastric or hypogastric in small bowel
obstruction
Generalized in large bowel obstruction
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25. Local signs in the abdomen are:
Inspection:
Scar
Distension, central in small bowel obstruction and
peripheral in large bowel obstruction
Visible peristalsis
SIGNS
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26. Palpation:
Abdominal mass may suggest carcinoma or
strangulated bowel.
Rigidity and rebound tenderness , indicates ischemia
& peritoneal irritation.
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27. Percussion:
Resonance because of gas filled bowel
Tenderness on percussion indicates the presence of
peritonitis.
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28. Auscultation:
Bowel sounds
Tympani
Metallic clicks as pressure is raised if much gas is
present in the bowel.
Gurgling borborygmi if gas and fluid are present in
the bowel.
Silence if generalized peritonitis or paralytic ileus is
present.
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29. On rectal examination:
Impacted feces
Rectal cancer
Blood on finger which maybe present with mesenteric
artery occlusions, intussusception or Volvulus.
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32. 4 - What is the cause?
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1 - Previous abdominal surgery and features of small
bowel obstructions suggest adhesions, The attacks may
have been recurrent
2 - Large bowel obstruction and history of constipation
with intermittent mucous or bloody diarrhea suggest
carcinoma of the colon
3 – No previous operations and symptoms of small bowel
obstruction suggest obstructed hernia or an
uncommon cause such as congenital band, internal
hernia or mesenteric occlusion.
36. 5 – Management
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Non operative :
• Simple obstruction, No strangulation .
• Gastrointestinal decompression: NG tube
• IV fluid
• Antibiotics
Operative:
• Usually surgery
• Replace fluid before surgery