The approach to clinical conundrums by an expert clinician is revealed through presentation of an actual patientThe patient presents with gastrointestinal symptoms following a trip to China. He may have an infection that began in the respiratory system and now is causing some gastrointestinal symptoms, like Legionnella. If he had received antibiotics, the diarrheal illness could be a complication. With his recent travel to China, typical enteric pathogens would have to be considered: enterotoxigenic E. coli, Shigella, Salmonella, Campylobacter, or perhaps Giardia.He was admitted and treated with intravenous fluids and ciprofloxacin for presumed gastroenteritis. He was discharged the next day but returned 2 days later because of continued nausea and vomiting and limited oral intake. He was febrile, to 38.9°C, with chills. The results of an abdominal exam were normal. Stool studies for Salmonella, Shigella, Campylobacter, Yersinia, enterotoxigenic E. coli, Giardia, and Cryptosporidium were negative. No blood parasites were seen. The white-cell count was 3900/ mm 3 with a normal differential count. Hemoglobin level, platelet count, serum electrolytes and creatinine were normal. He was readmitted for intravenous fluids.