GI Flashcards
Define intestinal obstruction
Blockage of the lumen of the gut
Arrest of onward propulsion of intestinal contents
Name 3 broad types of causes of intestinal obstruction
- Intraluminal obstruction = something in the bowel
- Intramural obstruction = something in the wall of the bowel
- Extraluminal obstruction = something outside of the bowel
Give 3 causes of intraluminal obstruction of the intestine
- Tumour - carcinoma, lymphoma
- Diaphragm disease
- Meconium ileus
- Gallstone ileus
What is diaphragm disease?
Mucosa/submucosa fold due to fibroid diaphragm leaving a pinhole lumen
What is thought to cause diaphragm disease?
NSAIDs
Give 3 causes of intramural obstruction of the intestine
- Inflammatory disease = Chron’s, Diverticulitis
- Tumours
- Neural = Hirschsprung’s disease
Describe how Crohn’s disease can cause intestinal obstruction
Crohn’s disease –> fibrosis –> contraction –> obstruction
Describe how diverticular disease can cause intestinal obstruction
Out pouching of mucosa –> faeces trapped –> inflammation in bowel wall –> contraction –> obstruction
What is Hirschsprung’s disease?
A congenital condition where there is a lack of nerves in the bowel –> no ganglion cells –> no contraction –> distal obstruction and gross dilation of the bowel
Give 3 causes of extraluminal obstruction of the intestine
- Adhesions
- Volvulus
- Peritoneal tumour
What are adhesions?
Fibrous bands stick 2 bits of bowel together so bowel is pulled and distorted
What causes adhesions?
Often formed after abdominal surgery (pelvic, gynaecologist, colorectal)
What is volvulus?
Bowel twisting around each other cuts off blood supply/ lumen
Risk of ischaemia, necrosis and perforation
Which areas of the bowel are most likely to be affected by volvulus?
Occurs in areas of bowel that have mesentery
Often in the sigmoid colon
Give 4 common causes of small bowel obstruction in adults
- Adhesions
- Hernias
- Crohn’s disease
- Malignancy
Give 3 common causes of small bowel obstruction in children
- Appendicitis
- Volvulus
- Intussusception
What is intussusception?
One part of the intestine telescopes into another section of the intestine
Caused by force in-balances
Give 5 symptoms of small bowel obstruction
- vomiting more common
- periumbilical
- cramping and intermittent pain
- lasts for a few minutes at a time
- Nausea and anorexia
- Early feculent vomit
- Diffuse colicky pain
- Late constipation
- Distention
- Tenderness
- bowel sounds
Does abdominal distension occur more distal or proximal to an intestinal obstruction?
More distal = greater distension
What investigations might you do in someone who you suspect to have a small bowel obstruction?
- FBC
- abdominal x-ray - shows central gas shadow that completely cross the lumen, distended loops of bowel proximal to obstruction, fluid levels seen
- CT - gold standard to localise lesion accurately
What is the management/treatment for small bowel obstruction?
- Fluid resuscitation
- Bowel decompression
- Analgesia and antiemetics
- Antibiotics
- Surgery - laparotomy, bypass segment, resection
Which is more common, small or large bowel obstruction?
Small bowel obstruction = 60-75% of intestinal obstruction
What can untreated intestinal obstruction lead to?
- Ishcaemia
- Necrosis
- Perforation
Give 2 common causes of large bowel obstruction
- Colorectal malignancy - most common in UK
2. Volvulus - more common in Africa