Intestinal Obstruction

Question 1

Define Intestinal Obstruction

Answer 1

Mechanical disruption in the latency of the GI tract and flow of intestinal contents, resulting in emesis, absolute constipation and abdominal pain

Question 2

Aetiology of Intestinal Obstruction

Answer 2

Small bowel: adhesions (previous surgery) | hernia + incarceration, strangulation | Crohn’s | malignancy | appendicitis

Large bowel: malignancy “ volvulus | diverticular disease | hernia | foreign bodies

Question 3

What is the difference between partial/incomplete obstruction, complete obstruction, simple obstruction and complicated obstruction

Answer 3

Partial/incomplete: passage of flatus and occasionally stool

Complete: emergency where the intestine is completely obstructing flatus and stool, associated with peritonitis

Simple: intestinal blockage in the absence of peritonitis

Complicated: emergency where the obstruction has progressed to ischaemia, gangrene or perforation

Question 4

Risk factors for small and large bowel Intestinal Obstruction

Answer 4

Small: previous abdominal surgery, malrotation, Crohn’s, hernias, appendicitis, malignancy, intussusception, volvulus

Large: older, female, mental illness, megacolon,

Question 5

Symptoms and signs of small bowel Intestinal Obstruction

Answer 5

Constipation (flatus or stool)
Intermittent abdominal pain (Cramping, severe)
Nausea and vomiting 
Abdominal distension
Fever
Groin swelling

Abdominal distension and tenderness
Abdominal mass
Palpable rectal mass
Peritonitis: guarding, patient still, rebound tenderness, fever, tachycardia
Bowel sounds high pitched and tinkling

Question 6

Symptoms and signs of larger bowel Intestinal Obstruction

Answer 6

Colicky abdominal pain (increasing, constant, pain on movement, coughing or deep breaths)
Abdominal distension
CHange in bowel habits with hard faeces or soft stools
Recent weight loss
Rectal bleeding 
Fever 
Tenesmus 
Groin swelling 
Nausea and vomiting 

Abdominal distension
Tympanic abdomen on percussion
 Empty rectum + rectal bleeding 
Abnormal bowel sounds 
Palpable rectal mass or abdominal mass. abdominal tenderness
Bowel sounds high pitched and tinkling

Question 7

Investigations for small bowel Intestinal Obstruction

Answer 7

CT: Evidence of bowel ischaemia and identify cause e.g. mass, appendicitis, hernia, gallstone, volvulus
AXR: Gasesous small bowel distension (>3cm). Bowel is central + visible valvulae conniventes
CXR: Check for perforation (pneumoperitoneum)

Urinalysis: rule out DKA
ECG: may show arrhythmia

VBG: lactate raised
FBC: leucocytosis
CRP: elevated
U+Es: hyponatraemia, hypokalaemia, elevated Ur + Cr (dehydration)
Lipase/amylase: check for pancreatitis 
Glucose: check for DKA 
Clotting, G+S, X-match: surgery 
Beta-hCG: exclude pregnancy 

Water-soluble contrast study/gastrograffin follow through: for those with failure to improve after management

Question 8

Investigations for large bowel Intestinal Obstruction

Answer 8

Contrast enema: obstruction to contrast at the site of lesion

FBC: leucocytosis, possible anaemia
Electrolytes: check for dehdyration or sepsis
Renal function: Ur or Cr elevated
Amylase/lipase: elevated
Coagulation profile: check for coagulopathy

CXR: exclude perforation
AXR: gaseous distension or large bowel >6cm OR volvulus, haustra seen
Flexible/rigid endoscopy ± biopsy: exclude malignancy

Question 9

Management for small bowel Intestinal Obstruction

Answer 9

1. Supportive care (fluid resus, bowel decompression, analgesia)
2. Nasogastric decompression + NBM
3. ± emergency surgery, correction of underlying cause, exploratory laparotomy

Question 10

Management of large bowel Intestinal Obstruction

Answer 10

1. Supportive (oxygen, IV fluids, correct electrolytes)
2. ± blood transfusion
3. Catheterise + monitor urine output
4. Nasogastric decompression
5. Antibiotics
6. Emergency surgery

Question 11

Complications of Intestinal Obstruction

Answer 11

Intestinal necrosis 
Sepsis
Multi-organ failure
Intra-abdominal abscess
Short bowel syndrome
Perforation + peritonitis 
Death