Question

While recovering in the surgical ward, a 65-year-old man develops acute-onset, severe abdominal pain. He is currently 8 days status post an open ventral hernia repair with mesh placement. His initial recovery was uncomplicated; he began passing flatus on the fourth day after surgery and was tolerating a regular diet. Over the past 24 hours, he has experienced progressive abdominal distension, nausea, and two episodes of bilious vomiting. He has not passed flatus since the pain began. His temperature is $38.9^\circ\text{C}$ ($102.0^\circ\text{F}$), blood pressure is $88/50 \text{ mmHg}$, pulse is $122/\text{min}$, and respirations are $22/\text{min}$. Physical examination reveals a markedly distended abdomen. There is diffuse tenderness with involuntary guarding and rebound tenderness, most prominent in the periumbilical region. Bowel sounds are absent. Laboratory studies show a leukocyte count of $18,500/\text{mm}^3$, a serum bicarbonate level of $14 \text{ mEq/L}$, and a lactate level of $4.2 \text{ mmol/L}$. An upright abdominal radiograph demonstrates multiple dilated loops of small intestine with prominent air-fluid levels and a paucity of colonic gas. Which of the following is the most appropriate next step in management?