Soru

An 82-year-old man is brought to the emergency department from a long-term care facility due to progressive abdominal swelling and a lack of bowel movements for the past three days. He has a history of Parkinson disease, hypertension, and chronic constipation. His medications include carbidopa-levodopa, amlodipine, and a daily multivitamin. On arrival, his temperature is 37.1°C (98.8°F), blood pressure is 138/82 mm Hg, pulse is 86/min, and respiratory rate is 16/min. Physical examination reveals a markedly distended, tympanitic abdomen. There is mild diffuse tenderness to palpation, but no guarding, rigidity, or rebound tenderness. Digital rectal examination demonstrates an empty rectal vault. Laboratory studies reveal a leukocyte count of 8,200/mm³ and normal serum electrolytes. A plain abdominal radiograph demonstrates a massively dilated large bowel loop resembling an inverted U-shape extending from the pelvis toward the right upper quadrant, with a loss of haustral markings. Which of the following is the most appropriate next step in management?