Final answer:
Mr. Ivan's complaint represents subjective information, which includes symptoms that only the patient can feel and report, like nausea and upset stomach.
Step-by-step explanation:
Mr. Ivan's report of having an upset stomach and feeling nauseated is an example of subjective information. Unlike signs, which can be observed and measured objectively, symptoms of disease are personal experiences reported by the patient and cannot be clinically confirmed or objectively measured.
Symptoms such as nausea and loss of appetite are subjective because they are what the patient feels and are communicated to the healthcare provider. Clinicians may use tools like the Wong-Baker Faces pain-rating scale or measure skin conductance fluctuations to attempt to quantify these subjective experiences.