Snapshot A 25-year-old man presents to his primary care physician for evaluation of diarrhea. He had recently gone to Mexico for spring break, where he stayed in a hostel with his friends. He spent a lot of time on the beach, swimming in caves, and hiking. He reports having onset of watery diarrhea about a week ago. He has not had any fevers, nausea, or vomiting. He does recall eating multiple rounds of raw oysters while in Mexico. He is found to be dehydrated, with poor skin turgor and dry mucous membrane. Introduction Overview login to view 3 more bullets Epidemiology login to view 8 more bullets Etiology login to view 13 more bullets Pathogenesis login to view 26 more bullets Infectious Bloody vs Watery Diarrhea Bloody Diarrhea Watery Diarrhea Campylobacter E. histolytica Enterohemorrhagic E. coli Enteroinvasive E. coli Non-thypoidal Salmonella Shigella Y. enterocolitica C. difficile C. perfringens Enterotoxigenic E. coli Giardia Cryptosporidium V. cholerae Rotavirus Norovirus Adenovirus S. aureus High Yield Risk Factors Exposure Risk Factors Associated Organisms Daycare - Rotavirus, astrovirus, calicivirus, Campylobacter, Shigella, Giardia, Cryptosporidium Food Dairy Campylobacter, Salmonella Food Eggs Salmonella Food Beef E. coli Food Poultry Campylobacter, Salmonella Food Pork C. perfringens, Y. enterocolitica Food Seafood Astrovirus, Vibrio Food Oysters Calicivirus, Vibrio Food Rice/pasta Bacillus cereus Water exposure Swimming pools Shigella Water exposure Contaminated water with cysts Giardia, E. histolytica, Cryptosporidium Travel history "Traveler's" diarrhea E. coli, Giardia, Salmonella, Shigella, Campylobacter Travel history Camping/hiking Giardia Past medical history Antibiotics/hospitalization C. difficile, rotavirus Pets Dog feces Yersinia enterocolitica Pets Turtles/reptiles Non-typhoidal Salmonella Pets Other animals/pets Campylobacter Presentation Symptoms login to view 12 more bullets Physical exam login to view 5 more bullets Studies Acute diarrhea does not routinely require laboratory evaluation, unless clinical presentation includes login to view 6 more bullets Serum labs login to view 1 more bullet Stool studies login to view 7 more bullets Differential Chronic diarrhea, which lasts 4 weeks or more, suggests other etiologies, such as fat malabsorption syndrome Chronic Diarrhea Malabsorption syndromes Celiac disease Lactose intolerance Pancreatic insufficiency Diabetic neuropathy Inflammatory bowel disease Crohn disease Ulcerative colitis Other gastrointestinal causes Microscopic colitis Irritable bowel syndrome Endocrinological Carcinoid Gastrinoma Drug-induced Quinidine Colchicine Chemotherapy Other Severe combined immunodeficiency Arsenic poisoning Vitamin C toxicity Vitamin B3 deficiency Treatment Medical login to view 18 more bullets Complications Dehydration