Which initial investigations should be performed in a patient suspected of having a non-mechanical bowel obstruction?

Initial investigations for a patient suspected of having a non-mechanical bowel obstruction should include:

• A full blood count, urea and electrolytes, and C-reactive protein to assess for inflammation and metabolic disturbances.
• Imaging with a contrast-enhanced CT scan of the abdomen and pelvis to confirm the diagnosis, identify the cause, and guide management. If contrast CT is contraindicated, alternatives include non-contrast CT, MRI, or ultrasound depending on local expertise.
• Additional investigations may be guided by clinical context, but initial focus should be on blood tests and imaging to differentiate non-mechanical obstruction from other causes such as complicated diverticulitis or malignancy.

These investigations help confirm the diagnosis, assess severity, and exclude complications such as ischemia or perforation, which are critical in non-mechanical bowel obstruction management.

NICE NG147,NICE NG12