A 27-year-old woman presents with abdominal pain, bloody diarrhea, and nausea for the past 6 weeks. She has lost 4.5 kg (10 lb) over this time period. She has an insignificant past medical history and denies alcohol or illicit drug use. She has a temperature of 38.7°C, blood pressure of 80/48 mmHg, heart rate of 124 beats per minute, and a respiratory rate of 18 breaths per minute. Physical examination demonstrates abdominal distention and tenderness to palpation in all four quadrants. The patient has diminished bowel sounds. Rectal examination is performed and gross blood mixed with mucous is appreciated. The patient’s leukocyte count is severely elevated at 28,000/mm3 .
Which of the following is the initial test of choice in the diagnostic workup of this patient’s suspected condition?
A. Abdominal ultrasoundAbdominal x-ray. This patient is demonstrating signs and symptoms consistent with inflammatory bowel disease, likely ulcerative colitis (abdominal pain, bloody diarrhea, nausea). She is hemodynamically unstable and has hypotension, tachycardia, leukocytosis, and fever. This presentation is suspicious for toxic megacolon, which is associated with a high mortality rate. To diagnose toxic megacolon, there must be hemodynamic instability, leukocytosis and/or anemia, and signs of colonic distention on abdominal x-ray (colon must be dilated >6 cm). (A, C, D) These are not helpful in diagnosing toxic megacolon. In fact, colonoscopy can be harmful due to its risk for colonic perforation.