Intestinal obstruction & ileus

• What is an intestinal obstruction?

  Physical obstruction prevents the flow of faeces through the intestines

  Blockage -> back pressure through GIT -> vomiting
• What is a large bowel obstruction?

  Medical emergency

  Intestines' normal passage of food, fluids & gas is impeded -> immediate medical intervention
• What are the common causes of large bowel obstruction?

  Malignancy

  Strictures (often secondary to diverticular disease, IBD, post-surgical anastomosis)

  Volvulus

  Hernias

  Adhesions
• What are the signs & symptoms of large bowel obstruction?

  Cramping abdo pain

  Bloating

  Absolute constipation (inability to pass wind/faeces)

  Potential nausea & vomiting (faeculent vomiting)
• Pathophys - large bowel obstruction

  Obstruction of bowel -> no gastric contents/gas can pass through -> increased colonic pressure -> dilation of bowel proximal to site of obstruction

  Ongoing dilation & pressure -> reduced blood flow to bowel -> bowel mucosal ulceration, full thickness wall necrosis & potentially perforation
• What are the DDx of large bowel obstruction?

  Small bowel obstruction

  Pseudo-obstruction

  Toxic megacolon

  Constipation/faecal loading
• What are the Inx for large bowel obstruction?

  Obs

  Full Hx & examination

  Bloods (FBC, U&Es, ABG/VBG, LFTs, CEA)

  Abdo XR

  CT abdo
• What is the management of large bowel obstruction?

  IV fluids

  NG tube (to decompress bowel)

  Anti-emetics

  Nil by mouth

  Abx (if signs of perforation)

  Treat underlying cause

  Flexible sigmoidoscope

  Surgery (resection)
• What is a small bowel obstruction?

  Partial or complete blockage of the small intestine -> disrupting normal passage of contents
• What are the common causes of small bowel obstruction?

  Adhesions

  Intra-abdominal hernia

  Crohn's disease

  Malignancy

  Volvulus
• Pathophys - small bowel obstruction

  Obstruction -> prevents normal food passage -> collapse of bowel distal to obstruction & dilation of proximal bowel (fluid * gas buildup) -> colicky abdo pain, nausea, vomiting, electrolyte & fluid loss (Na+, K+, H+, Cl-) -> metabolic alkalosis, hypokalaemia & hypovolaemia

  Over time -> bowel wall oedema -> compromises venous drainage & arterial perfusion -> risk of bowel ischaemia, infarction, necrosis & perforation
• What are the signs & symptoms of small bowel obstruction?

  Absence of passing flatus or stool

  Abdo pain (initially colicky, then becomes continuous)

  Nausea & vomiting (bilious/faecal)

  Bloating

  Abdo distension

  Bowel sounds (initially tinkling, may be reduced)

  Abdo tenderness

  Fever

  Tachycardia
• What are the Inx for small bowel obstruction?

  Obs

  Full Hx & examination

  Bloods (FBC, U&Es, ABG/VBG, amylase)

  Abdo XR (absence of air in rectum may indicate complete obstruction)

  Erect CXR (look for pneumoperitoneum)

  CT
• What are the DDx of small bowel obstruction?

  Large bowel obstruction

  Paralytic ileus

  Appendicitis

  Pseudo-obstruction
• What is the management of small bowel obstruction?

  A-E approach

  NG tube

  IV fluids

  Electrolyte repletion

  Nil by mouth

  Gastrografin

  Surgery (if conservative management doesn't work)

  • adhesionolysis
  • bowel resection
  • closure of hernias
  • tumour resection
• What are the possible complications of small bowel obstruction?

  Bowel ischaemia

  Sepsis

  Short bowel syndrome (following surgery)
• What is ileus?

  Reduced motility of GIT, secondary to a failure of peristalsis -> full/partial paralysis of intestinal muscles -> functional bowel obstruction
• When does ileus usually resolve?

  2-7 days (with conservative management)
• What are the common causes of ileus?

  Injury to bowel

  Handling of bowel during surgery

  Inflammation/infection in, or nearby, the bowel (e.g. peritonitis, appendicitis, pancreatitis, pneumonia)

  Electrolyte imbalance
• What are the signs & symptoms of ileus?

  Vomiting (esp. green bilious vomiting)

  Abdo distension

  Diffuse abdo pain

  Absolute constipation

  Lack of flatulence

  Absent bowel sounds
• What are the Inx for ileus?

  Obs

  Full Hx & examination

  BM

  Bloods (FBC, CRP, U&Es)

  CT abdo

  Abdo XR

  USS (common in paeds)
• What are the DDx of ileus?

  Mechanical bowel obstruction

  Pseudo-obstruction (acute distention of the colon)
• What is the management of ileus?

  Treat underlying cause

  Nil by mouth (possible limited water sips)

  NG tube

  IV fluids

  Mobilisation (helps peristalsis)

  TPN

  Analgesia (avoid opioids)