An unusual case of SIADH.

Presentation A 67-year-old male resident of Florida initially presented to another institution with an 8-week history of fatigue, loss of appetite, abdominal pain, and diarrhea that led to muscle wasting and a more-than-20% weight loss. The patient complained of poor appetite, early satiety, and intermittent right upper quadrant abdominal pain associated with nausea and vomiting, but no hematemesis, hematochezia, or melena. The patient was having multiple daily episodes of loose stools that did not contain mucus or blood. He denied having fevers, chills, night sweats, headaches, visual changes, dysphagia, odynophagia, cough, chest pain, dyspnea, orthopnea, edema, bleeding, or recent exposure to antibiotics. A review of systems was otherwise normal. The patient was not taking any scheduled medications at the time of his presentation. He denied smoking or heavy alcohol or illicit drug use. The patient had traveled to South America several times over the past few years, but he denied having traveled to other destinations, being exposed to animals or ticks, or consuming raw meat or unpasteurized dairy products. The patient worked in a healthcare facility and had a past medical history of hypertension, hypothyroidism, anal squamous carcinoma in situ, and diverticulitis.