Intestinal obstruction occurs when the contents of the intestine are blocked from passing through due to a partial or complete blockage. It can be classified as mechanical or functional, and partial or complete. The pathophysiology involves proximal dilation and paralysis of the bowel above the obstruction. Causes include adhesions, hernias, tumors, and impacted stool. Diagnosis involves evaluating symptoms of pain, vomiting, distention and constipation along with imaging tests. Management consists of resuscitation, monitoring, conservative treatment with NG tubes and IV fluids or surgical intervention if signs of strangulation or perforation are present.

1. Intestinal Obstruction
Prepared by Ahmad Zaki and Zurina
Supervisor : Dr Viknes

2. Outlines
Definition
Classifications
Pathophysiology
Causes
How to diagnose
Management
Take home messages

3. Definition
• Intestinal obstruction is a partial or complete blockage
of the bowel that prevents the contents of the
intestine from passing through.

4. Classification
• Mechanical and functional
• Partial and complete
• Simple and strangulated
• Acute and subacute

5. Obstruction
Proximal
Dilates
Proximal peristalsis
will increase to
overcome the
obstruction
it will continue to
dilates
reduction of
peristaltic strength
resulting in flacidity
and paralysis
Obstruction
Below/distal
Exhibition normal
peristalsis and absorption
Until it become empty
collapses
abdominal
pain,
distention,
vomiting and
absolute
constipation.
Pathophysiology
for Mechanical IO

6. Varieties
underlying causes
Systemic generation of
endocrine and inflammatory
mediators
Activation of
inhibitory spinal
reflex arcs
Failure of
transmission of
peristaltic wave
Stasis
Accumulation of
fluid and gas
Abdominal Distension,
vomiting,
absence of bowel
sound and absolute
constipation
Pathophysiology
for Functional IO

7. INTRALUMINAL
- Faecal impaction
- Foreign bodies
- Bezoars
- Gallstones
INTRAMURAL
- Volvulus
- Intussusception
- Malignancy
- Stricture
EXTRAMURAL
- Bands / adhesions
- Hernia
Causes
INTESTINAL
OBTRUCTION
Paralytic Ileus
Pseudo- obstruction
FUNCTIONAL
MECHANICAL

8. • ELDERLY – carcinoma, diverticulitis,
sigmoid volvulus
• ADULT – hernia, adhesion, carcinoma
• PAEDIATRICS – intussusception, congenital
hypertrophic pyloric stenosis, atresia
(duodenum, ileum), meconium obstruction,
volvulus neonatorum

9. How to diagnose?
• Thorough history and clinical examination
• Investigations
– Biochemical test
– Radiology

10. History
4 cardinal symptoms
• Abdominal pain
• Vomiting and nausea
• Abdominal distention
• Absolute constipation
Others: dehydrations, hypokalaemia, pyrexia,
abdominal tenderness, high pitched bowel
sound.

11. 1) Pain
• first symptom, occurs suddenly and usually severe.
• Nature : colicky, coincide with peristalsis  constant,
diffuse as distension increases.
• severe pain  indicative of strangulation.
2) Vomiting
• The more distal the obstruction, the longer interval
between the onset of symptoms and nausea/vomiting.
• As obstruction progresses the character of the vomitus
alters (digested food  faeculent material; as a result
of the presence of enteric bacterial overgrowth)

12. 3) Distension
• Small bowel: dependent on the site of the obstruction
and is greater the more distal the lesion.
• Colonic obstruction: delayed distension
• Visible peristalsis may be present.
4) Constipation
• Absolute or relative.
– Absolute constipation COMPLETE intestinal obstruction.
• The rule that constipation is present in intestinal
obstruction does not apply in:
– Richter’s hernia; gallstone obturation; mesenteric vascular
occlusion; obstruction associated with pelvic abscess;
partial obstruction (faecal impaction/colonic neoplasm)
~diarrhoea may often occur.

13. The clinical features vary according to:
• the location of the obstruction
• the age of the obstruction
• the underlying pathology
• the presence or absence of intestinal ischaemia.
■ In high small bowel obstruction,
vomiting occurs early and is profuse with rapid
dehydration. Distension is minimal
■ In low small bowel obstruction,
Vomiting is delayed. pain is predominant with central
distension.
■ In large bowel obstruction,
distension is early and pronounced. Pain is mild and
vomiting and dehydration are late.

14. Physical examination
Inspection
• Visible scar -band
-adhesion
Palpation
• hernial orifices
• large, slightly tender,
mobile
• mass changes its position
with colicky pain
• tender indurated mass
• hard impacted masses
-incarcerated
-strangulated hernia
- torsion
- intussusception
-mass of Ascaris worms
- intraperitoneal abscess
- fecaloma

15. Percussion - tympanic sound
Auscultation -runs of borborygmi
-tinkling high pitched musical
sounds
Rectal examination
• fresh blood and mucus
• hard mass of faeces
• hard mass in the
rectovesical pouch
-strangulating lesion
-carcinoma of large gut
-intussusception
- constipation
-extraintestinal tumour

16. Investigations
Biochemical test
• FBC
• BUSE
• Arterial blood gasses
• Clotting profile
• Optional (ESR, CRP, Hepatitis
profile, tumour markers)
- high Hb and hematocrit
- leukocytosis
- Anaemia
- electrolytes depletion
(hypokalemia, hyponatreamia)
-- acidosis

17. • X-RAYS -Gas pattern
-Fluid level
-Masses shadow
-Fecal pattern
• ULTRASOUND -free fluid
-masses
-mucosal folds
-pattern of paristalsis
• CT, MRI, Contrast studies -level of obstruction
-partial or complete
-cause of the obstruction
Radiology

18. Large Bowel: Small Bowel:
•Peripheral
•Presence of haustration, diameter
>8 cm
•distended caecum a rounded gas
shadow in the right iliac fossa. >10cm
diameter.
•Central
•jejunum  valvulae conniventes
•Ileum  featureless
•Diameter >5 cm
•No gas is seen in the colon

19. Multiple air fluid levels located
centrally-small bowel obstruction
Small bowel volvulus-
coffee bean appearance.

20. Management
• Early management
• Conservative
• Operative

21. Early management
• Resuscitation
– Oxygen therapy (if necessary)
– Correct dehydration and electrolytes
– IV antibiotics-IV cefobid 1gm bd, IV flagyl 500 mg tds
• Close monitoring
– Temperature,Pulse,BP,Urine output, Central venous
pressure
• Regular re-evaluation
• Keep nil by mouth
• Nasogastric tube- 4hourly aspirate and free flow
• Appropriate analgesia

22. Conservative
If obstruction presumed to be due to adhesions and there are no features of
peritonism,  conservative management may be consider.
– Nasogastric tube
• to help decompress the dilated bowel
– CBD
• To monitor urine output
– IV fluid
• Normal saline or Hartman’s for intravascular volume depletion
– Electrolytes correction
• Guided by test results
– Analgesic
• Opioid pain relievers may be used for patients with severe pain
– Antibiotic
• If bowel ischemia or infarction is suspected

23. Operative
Principles of surgical intervention for obstruction
• Management of:
– The segment at the site of obstruction
– The distended proximal bowel
– The underlying cause of obstruction

24. Indications for surgery
• Immediate intervention:
– Evidence of strangulation (eg:hernia)
– Signs of peritonitis resulting from perforation or ischemia
• In the next 24-48 hours
– Clear indication of no resolution of obstruction ( Clinical,
radiological).
– Diagnosis is unclear in a virgin abdomen

25. Take home messages
• The 4 main Cardical signs of intestinal
obstruction are Abdominal pain, Abdominal
distention, Vomiting and Constipation.
• Always examine for hernia orifice.
• Request for Supine, Erect and CXR.
• Provide adequate resusitation to the patient.
• Be attentive of signs of peritonitis resulting
from perforation or ischemia of bowel.