The 78-year-old resident of a nursing home is brought to the emergency department for abdominal pain that is not responsive to oxycodone. She takes captopril, atenolol, lovastatin, and glyburide in addition to the oxycodone. Upon assessment, her abdomen is full and mildly tender. She has positive bowel sounds and reports passing gas but no stools for 96 hours. She denies anorexia or vomiting. A digital rectal examination is performed and stool is found in the rectum. The nurse anticipates being ordered to perform which intervention for this patient?