Soru

During a shift in the emergency department, a physician evaluates an elderly female patient residing in a skilled nursing facility. The patient was transported for acute medical assessment due to a 72-hour history of obstipation, progressive abdominal distention, and frequent bilious emesis. Chart review notes a long-standing history of symptomatic gallstones that were managed expectantly due to high surgical risk. Currently, the patient is tachycardic and hypotensive with dry mucous membranes. Abdominal auscultation reveals high-pitched, tinkling bowel sounds over a distended, tympanic abdomen. The physician orders an acute abdominal plain radiograph series. The radiologist's read reports markedly distended jejunal and ileal loops with step-ladder air-fluid levels and an absence of colonic gas. Furthermore, there is a distinct branching tubular lucency over the hepatic silhouette and a 3.5-centimeter target-like radiopaque structure situated near the ileocecal valve. Based on the integration of these radiologic findings, which of the following best describes the fundamental pathophysiologic event that precipitated this condition?