Palpate for focal tenderness* (including guarding and rebound tenderness on palpation). Ensure to assess the patient’s fluid status, as third-spacing can occur in bowel obstruction. surgical scars, cachexia from malignancy, or obvious hernia) or abdominal distension. On examination, patients may show evidence of the underlying cause (e.g. *Initially of gastric contents, before becoming bilious and then eventually faeculent Absolute constipation – occurring early in distal obstruction and late in proximal obstruction.Vomiting – occurring early in proximal obstructions and late in distal obstructions.Abdominal pain – colicky or cramping in nature (secondary to the bowel peristalsis).The cardinal features of bowel obstruction are: *When the bowel is not mechanically blocked but does not work properly, for example because of inflammation, electrolyte derangement, or recent surgery, this is known as functional obstruction or paralytic ileus Urgent fluid resuscitation and careful fluid balance is required. This leads to secretion of large volumes of electrolyte-rich fluid into the bowel (often termed ‘third spacing’). Once the bowel segment has become occluded, gross dilatation of the proximal limb of bowel occurs, resulting in an increased peristalsis of the bowel.
Around 15% of acute abdomen cases are found to have a bowel obstruction. The term bowel obstruction typically refers to a mechanical blockage of the bowel, whereby a structural pathology physically blocks the passage of intestinal contents.