Differential Diagnosis for 21 Days or Traveler's Diarrhea

Single Most Likely Diagnosis

• Viral Gastroenteritis: This is the most common cause of traveler's diarrhea, often resulting from ingestion of contaminated food or water. Viruses such as norovirus and rotavirus are frequent culprits.

Other Likely Diagnoses

• Bacterial Gastroenteritis: Bacteria like E. coli, Salmonella, and Shigella are common causes of traveler's diarrhea, especially in areas with poor sanitation.
• Giardiasis: An intestinal infection caused by the parasite Giardia lamblia, often contracted through contaminated water.
• Food Poisoning: Caused by the consumption of food contaminated with bacteria, viruses, or toxins, which can lead to symptoms of diarrhea.

Do Not Miss Diagnoses

• Cholera: Although less common, cholera is a life-threatening disease caused by Vibrio cholerae, which can lead to severe diarrhea and dehydration if not promptly treated.
• Amoebic Dysentery: Caused by Entamoeba histolytica, this condition can lead to severe diarrhea, abdominal pain, and potentially life-threatening complications if not treated.
• Inflammatory Bowel Disease (IBD) Exacerbation: In patients with a history of IBD (Crohn's disease or ulcerative colitis), an exacerbation could present with similar symptoms and must be considered to avoid missing a significant flare-up.

Rare Diagnoses

• Cyclosporiasis: An intestinal infection caused by the parasite Cyclospora cayetanensis, which can cause prolonged diarrhea.
• Cryptosporidiosis: Caused by the parasite Cryptosporidium, this infection can lead to severe diarrhea, particularly in immunocompromised individuals.
• Yersiniosis: A bacterial infection caused by Yersinia enterocolitica, which can lead to diarrhea and abdominal pain, though it is less common than other causes of traveler's diarrhea.