Question

A 72-year-old man is evaluated on postoperative day 3 following a right total hip arthroplasty for a femoral neck fracture. He reports progressive abdominal distention, nausea, and an inability to pass flatus or stool for the past 48 hours. His medical history includes hypertension and benign prostatic hyperplasia. Current medications include lisinopril, tamsulosin, and intravenous morphine for pain control. Vital signs show a temperature of $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure of $130/80\text{ mm Hg}$, pulse of $92\text{/min}$, and respiratory rate of $16\text{/min}$. Abdominal examination reveals massive, tympanitic distension with diminished bowel sounds; there is no guarding or rebound tenderness. Laboratory studies show a serum potassium of $3.1\text{ mEq/L}$ and magnesium of $1.3\text{ mg/dL}$. A CT scan of the abdomen confirms diffuse dilation of the colon with a cecal diameter of $10.5\text{ cm}$ and no evidence of mechanical obstruction or perforation. The patient is diagnosed with acute colonic pseudo-obstruction (Ogilvie syndrome).

Arrange the following management interventions in the correct standard sequential order for this condition, progressing from the most appropriate initial action to the final therapeutic option for refractory disease.