This document discusses intestinal obstruction, including its definition, classification, causes, pathophysiology, diagnosis and treatment. Intestinal obstruction can be mechanical or functional. Mechanical obstruction has causes such as adhesions, hernias, tumors and volvulus. Diagnosis involves history, exam, labs, imaging and identifying the level and cause of obstruction. Treatment depends on the severity and includes resuscitation, conservative management or surgery to remove obstructions or resect non-viable bowel segments. Post-operative ileus is a common type of functional obstruction.

1. Intestinal Obstruction
By
Mohamed Mourad
Assistant Lecturer of General Surgery

2. Definition
• Any condition interferes with normal propulsion
and passage of intestinal contents.
Peristalsis is working
against a mechanical
obstruction
DYNAMIC
(MECHANICAL)
Result from atony of the
intestine with loss of normal
peristalsis, in the absence of
a mechanical cause.
or it may be present in a
non-propulsive form (e.g.
mesenteric vascular
occlusion or pseudo-
obstruction)
ADYNAMIC
(FUNCTIONAL)

3. Classification
Classification
Cause
mechanical
ileus
Duration
Acute
Chronic
Extent
Partial
Complete
Type
Simple Complex
Closed loop
strangulation

4. Mechanical obstruction
Intraluminal
• Impaction
• Foreign bodies
• Bezoars
• Gallstone
Intramural
• Congenital atresia
• Stricture
• Malignancy(15%)
Extramural
• Bands/ adhesion(40%)
• Hernia (12%)
• Volvulus
• Intussusception
• Tumor-benign/malignant

5. Mechanical obstruction
• This mechanical obstruction can be partial ( lumen
narrowed but allow transit some content) or complete (
lumen totally obstruction) this classify to:
A. Simple obstruction (no vascular impairment)
B. Closed loop ( both ends are obstructed e.g volvulus)
C. Strangulation obstruction

6. Functional obstruction
• Either paralysis or dysmotility of intestinal
peristalsis.
• Postoperative ileus is the most common form of
functional bowel obstruction.

7. Epidemiology
• 1% of all hospitalization
• 3% of emergency surgical admissions
• Adhesion is the most common cause of intestinal
obstruction
• Mortality rate range between
– 3% for simple bowel obstruction to
– 30% when there is strangulation or perforation

8. 40%
16%
14%
14%
10%
3% 3%
Adhesions
Hernia
Small Intest volvolus
Intussusception
Sigmoid volvolus
Ascaris
Large bowel tumor
80% with gangrenous bowel segments
70 % of the patients were below the age of 15 years
Intestinal obstruction
Pattern in Africa

9. Etiology
Mechanical bowel obstruction
• Small bowel obstruction:
– Adhesion 60%
– Hernia 20%
– Neoplasm 5%
– Volvulus 5%.
– Others: IBD - gall stone - foreign body - intussusception.
• Large bowel obstruction :
– Cancer 60%.
– Diverticular disease 15%.
– Volvulus 15%.
– Others: hernia – fecal impaction - IBD.

10. Etiology
Functional bowel obstruction
1. Vascular occlusion ileus.
2. Adynamic or inhibition ileus :
– Post operative.
– Metabolic causes: DKA- hyponateremia-hypokalemia –
hypomagnesaemia.
– Drugs: morphine –TCA-antacid-anticonvulsant.
– Intra-abdominal inflammation—sepsis—occult wound infection.
– Pneumonia—renal stone—retroperitoneal hematoma—fracture
spine and ribs.
3. Spastic ileus. ( intestine remain contracted and no propulsive)
causes are:
– Uremia.
– Porphyria.
– Heavy metal poison.

11. PATHOPHYSIOLOGY

12. Pathophysiology

13. Pathophysiology
(cont.)

14. Pathophysiology
Proximal
bowel dilated
& develops
altered
motility 
dilate 
reduce
peristaltic
strength 
flaccidity &
paralysis
(prev.
vascular
damage due
to inc.
intraluminal
pressure
Distal to obs.
Bowel
exhibits
normal
peristalsis &
absorbtion 
become
empty 
contract &
become
immobile
Distention is
by gas & fluid
-Gas: aerobic
& anaerobic
growth
-Fluid:
Digestive
juices &
retarded
absorption
Dehydration
&
electrolytes
loss: Reduced
oral intake,
defective
intestinal
absorption,
loses from
vomiting &
sequestration
in bowel of
lumen.

15. NOTE
• According to LAPLACE’s law: maximum pressure
is at the maximum diameter AREA
Caecum is at the greatest risk of perforation

16. Pathophysiology
• Dehydration results from:
– Reduced oral intake,
– Defective intestinal absorption,
– Loses from vomiting & sequestration in bowel of
lumen.

17. Diagnosis
History and physical examination
• Four cardinal symptoms
1. Pain
2. Vomiting
3. Distension
4. obstipation).
• Location and characteristic of pain??
• Examination :
o Vital signs.( PR-Temp-BP)
o Hydration status.
o Abdominal and rectal examinations

18. Physical Examination
• INSPECTION
– Abdominal distention, scars, visible peristalsis.
• PALPATION
– Mass, tenderness, guarding
– Examination of hernial orifices
• PERCUSSION
– Tympanic, dullness
• AUSCULTATION
– Bowel sound are high pitch and increase in frequency
– Or silent.

19. Difference between High & Low
intestinal obstruction
HIGH LOW
BEGINNING Acute Slow, insidious
GENERAL CONDITION Early compromission preserved
PAIN Crampy pain in paroxism Less intensity
VOMITING Early, profuse, biliary Late, feculent may be
absent
ABDOMINAL
DISTENTION
Moderate, upper
quadrant
Early, intense
CONSTIPATION + +++
ELECTOLYTES Cl, K, Na rapid loss Late hydro electrolytic
imbalance

20. Diagnosis
Laboratory
• CBC:
– Increase PCV (dehydration ) and increase in WBC.
• KFT:
– Increase in BUN and creatinine .
• Lactate concentration-amylase-lactic
dehydrogenase useful but not sensitive
– To rule out necrosis
• ABG:
– metabolic alkalosis and respiratory acidosis.

21. Diagnosis
Radiology
• CXR :
– Detect extra-abdominal condition present with bowel
obstruction e.g. pneumonia.
– Presence of pneumoperitoneum indicates perforated
viscus.

22. Diagnosis
Radiology
• Abdominal X-RAY
– Small bowel considered dilated when diameter more than 3
cm while proximal colon 9 cm and the sigmoid 5 cm.
– The cause of bowel obstruction can often determined
• Presence of pneumobilia suggest G.S ileus.
• Sigmoid and cecal volvulus produce pathognomnic images

23. Radiology
Fluid levels with gas above;
‘stepladder pattern’. Ileal
obstruction by adhesions; patient
erect.
Prone radiograph from a patient with
complete large bowel obstruction
shows distended lagre bowel in the
periphery of abdomen with
haustration.

24. NOTE
• According to LAPLACE’s law: maximum pressure
is at the maximum diameter AREA
Caecum is at the greatest risk of perforation

25. Diagnosis
Radiology
• Contrast studies:
– Indications are controversial.
– Identify site and often the cause of obstruction.
– Differentiate between colonic and distal small bowel
obstruction
– Differentiate between ileus-partial and complete
obstruction.
• Computed tomography:
– Recently become valuable in B.O especially when plain
films failed in diagnosis or suspect strangulation.
– Sensitivity 93% and specificity 100%
– Accuracy 94% in diagnosis of BO
Barium should not be used in
a patient with peritonitis

26. Treatment
• For optimal treatment to be instituted, five questions
must be answered:
• Is the diagnosis intestinal obstruction?. Is the obstruction is
mechanical? .
• What is the level of obstruction?.
• Is there evidence of bowel wall ischemia or perforation?.
• How sever is the associated systemic disorders?.

27. Treatment
A. Resuscitation.
B. Conservative treatment
1. Previous surgery.
2. Incomplete obstruction.
3. Advanced malignancy.
C. Indications for surgery
1. Generalized or localized peritonitis.
2. Perforation.
3. Strangulated hernia.
4. Closed loop
5. Failure to improve on conservative treatment.

28. Obstruction by Adhesions
• Peritoneal irritation local fibrin production
adhesions
• As early as 4 weeks post laparotomy. The
majority of patients present between 1-5 years
Colorectal Surgery 25%
Gynaecological 20%
Appendectomy 14%
• Prevention:
• good surgical technique, washing of the
peritoneal cavity with saline to remove clots, etc,
minimizing contact w/ gauze, covering
anastomosis & raw peritoneal surfaces

29. Treatment of adhesive obstruction
• Conservatively provided there is no signs of
strangulation; should rarely continue
conservative treatment for longer than 72 hours
• At operation, divide only the causative adhesion
and limit dissection.

30. Treatment of adhesive obstruction

31. Obstructed Hernia
• Commonest
– Femoral hernia
– ID inguinal
– Umbilical
– Others: incisional
• Ischaemia occurs initially by venous occlusion, followed by
oedema and arterial compromise.
• Strangulation is noted by:
• Persistent pain
• Discolouration
• Tenderness
• Constitutional symptoms
• Loss of impulse with cough

32. Management For Large Bowel
Obstruction
• Appropriate operations include:
• Right sided lesions – right hemicolectomy
• Transverse colonic lesion – extended right hemicolectomy
• Left sided lesions – various options

33. Management of Left Colonic
Obstruction
• Three-staged procedure
1. Defunctioning colostomy
2. Resection and anastomosis
3. Closure of colostomy
• Two-staged procedure
1. Hartmann’s procedure
2. Closure of colostomy
• One-stage procedure
• Resection, on-table lavage and primary anastomosis
• Total colectomy with ileorectal anastomosis

34. Volvulus
• A twisting or axial
rotation of a portion of
bowel about its
mesentery. When
complete it forms a
closed loop obstruction
• Relieved by
decompression per
anum.
• Surgery is required to
prevent or relieve
ischaemia
Features: palpable tympanic lump
(sausage shape) in the midline or
left side of abdomen.
Constipation, abdominal distension
(early & progressive)

35. Volvulus

36. Acute intussusception
• Occurs when one portion of
the gut becomes invaginated
within an immediately
adjacent segment.
• Common in 1st year of life
• Common after viral illness
enlargement of Peyer’s
patches
• Ileocolic is the commonest
variety in child.
• Colocolic intussusception
commonest in adult

37. Classically, a previously
healthy infant presents
with colicky pain and
vomiting (milk then bile).
Between episodes the
child initially appears
well.
Later, they may pass a
‘red currant jelly’ stool.
Red currant
jelly stools
Acute intussusception

38. Intussusception

39. Barium reduction of intussusception
Head of intussusception
is at hepatic flexure
Free flow of contrast into
distal small bowel indicates
complete reduction
Partial reduction

40. Post Operative Ileus
• Prevention
– Use of nasogastric suction and
– Restriction of oral intake until bowel sound and passage
of flatus return
– Maintain electrolyte balance
• Specific treatment:
– Removed primary cause
– Decompressed GI distension
– If prolong paralytic ileus , consider laparotomy exclude
hidden cause and facilitate bowel decompression

41. THANKSGOOD LUCKANY QUESTION??