The client is a 27-year-old male who had an exploratory laparotomy 8 days ago following a gunshot wound to the abdomen. The surgeons evacuated a large amount of blood in the peritoneum and repaired a liver laceration. The client was in the intensive care unit (ICU) for 4 days and in the surgical floor for 4 days. He started a regular diet 3 days ago but is now refusing to eat and has had several episodes of vomiting in the past 3 hours. Which action should the nurse take?