Editing Small bowel obstruction (section)

== '''Presentation''' ==

* Typical presentation:
** Colicky abdominal pain - crampy, paroxysms every 4-5 minutes but less frequently with distal obstructions
** Nausea/vomiting - more common with a higher obstruction. Vomitus becomes more faeculent as the obstruction becomes more complete and bacterial overgrowth occurs.
** Abdominal distension - as the intestine becomes more dilated - more prominent with distal obstructions
** Obstipation - often have associated small-volume diarrhoea, so bowels opening cannot exclude SBO
* Signs of strangulation - need to be interpreted together and in context
** '''Continuous pain''' (most important)
** Fever
** Tachycardia
** Localised tenderness and peritonism (not as useful)
** Leucocytosis (not sensitive or specific)
** Metabolic acidosis secondary to hyperlactataemia 
* Key points on review
** History
*** Surgical history
*** Hernias
*** Malignancy
** Exam
*** Distension with often visible peristalsis early on
*** Surgical scars
*** Auscultate borborygmi (hyperactive bowel sounds with audible rushes from the vigorous peristalsis)
*** Percussion - tympany
*** Check for hernias
*** You could technically do a PR exam to check for distal obstruction and blood, which could indicate malignancy, intussusception or infarction
* Bloods
** Often have a hypokalaemic, hypochloraemic, metabolic alkalosis
** High haematocrit expected due to dehydration