Final answer:
The area of confusion is the possible causes of the patient's gastrointestinal distress. Additional tests should be performed to determine the underlying cause and the appropriate treatment recommended by the doctor.
Step-by-step explanation:
The area of confusion between Lisa and the patient is the possible causes of the patient's severe gastrointestinal distress. The doctor should perform additional tests, such as a gastrointestinal endoscopy or a colonoscopy, to further evaluate the patient's condition and identify the underlying cause. The type of treatment recommended by the doctor will depend on the preliminary diagnosis, which can be determined through these additional tests. Treatment options may include medication, dietary changes, or surgical intervention.