36 hours after admission for evaluation of diffuse abdominal pain, a 42-year-old woman is still obstipated. She has a 9-year history of scleroderma. Current temperature is 100°F, pulse 110, respiratory rate 22, blood pressure 110/60. Abdomen is distended with colon dilation and white blood cell count is 14,000. Next step?
A) Administer laxatives and stool softeners
B) Perform a colonoscopy
C) Order a CT scan of the abdomen
D) Evaluate for perforation or ischemic colitis