1. A 35-year-old man presents with severe central abdominal colicky pain for the past 8 hours. It is

1. A 35-year-old man presents with severe central abdominal colicky pain for the past 8 hours. It is associated with vomiting and abdominal distension. He has also not moved his bowels since the onset of pain. He underwent an appendicectomy as a child. On examination the abdomen has central distension that is resonant on percussion. The abdomen is tense but non-tender. The bowel sounds are exaggerated and high-pitched. Abdominal X-rays show the presence of multiple air-fluid levels distributed mainly in the central abdomen.