Bowel obstruction

• Cardinal features of intestinal obstruction;
  • Vomiting
  • Colic
  • Constipation – doesn’t need to be complete
  • Distension
• Fermentation of intestinal contents causes ‘faeculent’ vomiting
• Active ‘tinkling’ bowel sounds

• An ileus is a functional obstruction due to reduced bowel motility. There is no pain and bowel sounds are absent
• Ask yourself, is the bowel strangulated? Is the patient more ill than you would expect. The pain is sharper and more constant than the central colicky pain of obstruction and tends to be localised

Management

• Strangulation and large bowel obstruction requires surgery soon while ileus and incomplete small bowel obstruction can be managed conservatively
• ‘Drip and suck’ – NGT and IV fluids, correcting any electrolyte balance
• A water soluble contrast follow through study may be helpful in determining the level of obstruction
• CT may show dilated fluid filled loops of bowel
• Surgery – strangulation requires emergency surgery as does a ‘closed loop obstruction’ – large bowel obstruction with tenderness over a grossly dilated caecum
• For less urgent large bowel obstruction there is time for a water soluble enema to try and clear the obstruction and correct fluid imbalance

Typical causes

• Constipation
• Hernias
• Adhesions
• Tumours
• Crohn’s disease
• Gallstone ileus
• Intussuception
• Diverticular stricture
• Volvulus

Paralytic ileus

• The cause of the obstruction is known to be the absence of peristaltic contractions
• Contributing factors include;
  • Abdominal surgery
  • Pancreatitis (or other cause of localised peritonitis)
  • Spinal trauma
  • Hypokalaemia
  • Hyponatraemia
  • Uraemia
  • Peritoneal sepsis
  • Drugs – tricyclics

Pseudo-obstruction

• Like mechanical GI obstruction but now cause is found
• Acute colonic pseudo-obstruction is called Ogilvie’s syndrome
• Predisposing factors include’
  • Puerperium
  • Pelvic surgery
  • Trauma
  • Cardiorespiratory disorders
• Neostigmine can be useful in treatment

Sigmoid volvulus

• When the bowel twists round on its mesentery -can produce severe, rapid, strangulated obstruction
• AXR – inverted U loop of bowel that looks a bit like a coffee bean
• Tends to occur in the elderly, constipated, co-morbid patient
• Can be managed by sigmoidoscopy and insertion of a flatus tube
• If not successfully treated can progress to perforation