1. INTESTINAL
OBSTRUCTION
Amina Al-Qaysi1

2. DEFINITION
Interruption of
normal passage
of intestinal
contents.

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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4. CAUSES
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 Dynamic:
1. Intraluminal:
Impaction
Foreign body
Bezoars
Gallstones
2. Intramural :
stricture
Malignancy
3. Extramural:
Bands/adhesions
Hernia
Volvulus
Intessusception
 Adynamic
Paralytic ileus
Mesenteric vascular
occlusion
Pseudo-obstruction

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
1. Large bowel cancer.
2. Sigmoid diverticular disease.
3. Sigmoid volvulus.
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7. 7

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9. 9

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:
1 – Retroperitoneal hematoma following lumber
fracture or lumber surgery
2 – Idiopathic
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12. COMMON CAUSES SBO
60%20%
10%
5%
5%
Adhesions
Neoplasms
Hernias
Crohns
Miscellaneous

13. PATHOPHYSIOLOGY
 Dilation proximal to obstruction (gas & fluid)
 Hyper-peristalsis
 Flaccidity & paralysis
 Dehydration due to :
1. Reduced oral intake
2. Defective intestinal absorption
3. Vomiting
4. Sequestration in bowel lumen

14. MECHANICAL OBSTRUCTION:
Three main types:
1 -Simple
2 – Closed-loop
3 - Strangulation
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15. 1 -SIMPLE OBSTRUCTION
 The bowel is usually occluded at one
level.
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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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20. Symptoms
The cardinal
features of bowel
obstruction are,
1. Pain
2. Vomiting
3. Constipation
4. Distension 20

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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23. Constipation
 Early in large bowel obstruction
 Absolute in complete obstruction
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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
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SIGNS

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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30. 2 – Is strangulation present ?
 Fever
 Tachycardia,
 Leukocytosis
 Constant pain
 Rebound Tenderness & rigidity
 Shock
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31. 3 – Is Dehydration present ?
 Tachycardia
 Hypotension
 Dry skin
 Dry mouth
 Poor skin turgor
 Small volume concentrated urine.
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32. 4 - What is the cause?
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.
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33.  Laboratory Examination
1. Complete blood count (WBC)
2. Serum electrolytes and amylase determination
3. Arterial blood gas analysis
INVESTIGATIONS

34. INVESTIGATIONS
 Radiologic Examination
1. Sigmoidoscopy (Carcinoma, Sigmoid Volvulus,
Inflammatory stricture)
2. Plain X-ray of the abdomen, erect
3. Single- contrast water-soluble enema study
4. CT Scan
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35. 35

36. 5 – Management
Non operative :
• Simple obstruction, No strangulation .
• Gastrointestinal decompression: NG tube
• IV fluid
• Antibiotics
 Operative:
• Usually surgery
• Replace fluid before surgery
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