<prompt> Answer this question truthfullyWhat are the possible diagnoses to consider for someone displaying symptoms of carcinoid syndrome?  <response>: <reason> Carcinoid syndrome must be differentiated from: Systemic mastocytosis Medullary thyroid carcinoma Irritable bowel syndrome Malignant neoplasms of the small intestine Benign cutaneous flushing Recurrent idiopathic anaphylaxis 