Pathology & Presentation of intestinal obstruction

Question 1

What are the 3 types of obstruction which can occur in the gut?

Answer 1

Intraluminal
Extraluminal
Intramural

Question 2

Give 3 example of causes of intra-luminal obstruction

Answer 2

• *Tumours**
• Life sided colon tumours present with obstruction earlier than right sided tumours (most common)
• *Diaphragm disease**
• Related to taking lots of NSAIDs
• Fibrotic reaction to those drugs
• *Gallstone ileus**
• Gallstone in gallbladder → inflammation in gallstone causes the gallstone to stick to the duodenum → necrosis of the gallbladder and gallstone passes into small intestine → blocking the ileum (rare)

Question 3

Give 3 examples of intramural obstruction

Answer 3

• *Inflammation**
• Chron’s disease
• Diverticular disease
• *Intramural Tumours**
• Tumour accumulates in the bowel wall and causes stenosis or blockage
• *Hirschman disease**
• Newborn with massive colon

Question 4

Give 3 examples of extraluminal obstruction

Answer 4

• *Adhesions**
• Fibrous bands of tissue within the peritoneum which pulls sections of the bowel together and causes blockage
• *Sigmoid volvulus**
• Sigmoid colon externally wraps around itself, stopping blood supply and causes a blockage
• *Peritoneal tumour**
• Can occur from all sorts of tumours and it affects the peritoneum causing blockage

Question 5

What are the cardinal features of intestinal obstruction?

What are some general findings in those with bowel obstruction?

Answer 5

• Vomiting/nausea (early vomiting suggests proximal bowel obstruction)
• Abdominal pain/colic (poorly localised)
• Complete constipation (Early in distal large bowel)
• Abdominal distension
• Tinkling bowel sounds

General features:

• Tachycardia
• Dehydration (hypotension, poor UO)
• Abdominal distension
• Visible peristalsis
• Obvious lump at site of obstruction

Question 6

What are the causes of small bowel obstruction?

Presentation?

Answer 6

• Adhesions
• Hernias

Rarer:
- IBD, malignancy, intussesception, volvus, foreign bodies

Presentation

• Pain - colicky - constant
• Nausea & vomiting
• Constipation - late
• Diarrhoea - early
• Abdominal distension
• Increased bowel sounds

Question 7

Causes of large bowel obstruction?

Presentation?

Answer 7

• Volvus
• Diverticular strictures
• Colon cancer

Rarer:

• Hernias
• Intussusceptions
• Ischaemic strictures

Presentation

• Abdominal distension
• Pain
• Constipation, nausea & vomiting - late features
• Tenderness, hyper resonant abdomen with normal or diminished bowel sounds

Question 8

Causes of gastric outlet obstruction?

Presentation?

Answer 8

• These are rare occurences
• chronic peptic ulcer
• advanced pancreatic cancer
• hypertrophic pyloric stenosis
• gastric paresis

Presentation
- N&V, satiety, fullness
Dehydration, malnutrition, weight loss, failure to thrive as baby, pain is uncommon

Question 9

What is sigmoid volvus?

What can occur if it is not treated?

Answer 9

• Occurs when the bowel twists on it’s mesentery which can produce severe, rapid strangulated obstruction
• It tends to occur in the elderly, constipated, comorbid patients and is managed by insertion of a flatus tube or sigmoidoscopy.
• If not treated, it can progress to perforation and fatal peritonitis.