Soru

A $78$-year-old man is evaluated in the surgical ward on postoperative day $4$ following an open reduction and internal fixation of a comminuted intertrochanteric femur fracture. His medical history includes hypertension, diet-controlled type $2$ diabetes mellitus, and chronic kidney disease stage II. Over the past $48$ hours, he has developed progressive, severe abdominal distension and nausea without vomiting. He has not passed flatus or had a bowel movement since the surgery. His pain is being managed with a patient-controlled intravenous hydromorphone pump.

Vital signs include a temperature of $37.1^\circ\text{C}$, heart rate of $88$/min, blood pressure of $135/85$ mmHg, and respiratory rate of $16$/min. On physical examination, the abdomen is massively distended and tympanitic to percussion throughout, with high-pitched, infrequent bowel sounds. There is diffuse mild tenderness but no rebound guarding or rigidity.

An initial portable supine abdominal radiograph demonstrates severe dilation of the entire colon, with the cecum measuring $10.5$ cm in diameter. A subsequent computed tomography (CT) scan of the abdomen and pelvis with water-soluble enteral contrast confirms marked colonic dilation without any transition point, mechanical obstruction, or signs of bowel ischemia, establishing the diagnosis of acute colonic pseudo-obstruction (Ogilvie syndrome).

Assuming the patient's condition ultimately proves refractory to each successive non-operative therapy without developing signs of peritonitis or perforation, arrange the following therapeutic interventions in the correct algorithmic sequence from first-line to last-resort management.