An 80-year-old man is admitted to the hospital complaining of nausea, abdominal pain, distention, and diarrhea. A cautiously performed transanal contrast study reveals an “apple core” configuration in the rectosigmoid. Appropriate management at this time would include A: Colonoscopic decompression and rectal tube placement B: Saline enemas and digital disimpaction of fecal mattrer from the rectum C: Colon resection and proximal colostomy D: Oral administration of metronidazole and checking a Clostridium difficile titer