A 43-year-old male client has presented to the emergency dep…

A 43-year-old male client has presented to the emergency department with vomiting that he claims is of a sudden onset. The client also states that the emesis has often contained frank blood in the hours prior to admission. His vital signs are stable with temperature 98.3°F (36.8°C), pulse 88, BP 140/87, and respiratory rate 18. Which potential contributing factor would the health care team suspect first?