Soru

An $81$-year-old male resident of a memory care facility is transported to the hospital due to progressive abdominal distension and failure to pass stool or flatus for the past three days. He has a history of vascular dementia, Parkinson disease, and chronic constipation. His daily medications include carbidopa-levodopa, donepezil, and scheduled senna. Vital signs show a temperature of $37.1^\circ$ C ($98.8^\circ$ F), blood pressure of $134/82$ mm Hg, pulse of $94$/min, and respiratory rate of $18$/min. On physical examination, the abdomen is markedly distended and tympanic to percussion. There is generalized mild tenderness to deep palpation, but no guarding, rebound tenderness, or rigidity is noted. Bowel sounds are high-pitched and infrequent. Laboratory testing reveals a leukocyte count of $9,500$/mm $^3$ and a serum lactate of $1.1$ mmol/L. An unenhanced abdominal computed tomography scan demonstrates a massively dilated loop of large bowel forming a U-shape in the pelvis, converging toward the left lower quadrant, accompanied by a mesenteric "whirl sign". No free intraperitoneal air or bowel wall pneumatosis is visualized. Which of the following is the most appropriate next step in management?