You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A patient is being investigated for chronic diarrhoea. Small intestinal mucosal biopsy shows PAS positive foamy macrophages. The diagnosis is probably - and explain in detail?
Whipple's disease is a rare condition characterised by infiltration of small imtestinal mucosa by foamy macrophages, which stain positive with periodic acid-schiff reagent. It is caused by infection with Gram positive bacillusTropheryma whipplei, which becomes resident in the bowel mucosa. Clinical features include diarrhea ,steatorrhea,weight loss,ascites, sacroiliitis,protein losing enteropathy, apathy,fits,pleurisy. Reference Harrison20th edition pg 1103