Differential Diagnosis for Gastroenteritis of Unknown Origin
Single Most Likely Diagnosis
- Viral Gastroenteritis: This is the most common cause of gastroenteritis, often presenting with watery diarrhea, and can vary significantly in the number of daily depositions. Viruses such as norovirus and rotavirus are common culprits.
Other Likely Diagnoses
- Bacterial Gastroenteritis: Bacteria like Salmonella, Shigella, and Campylobacter can cause gastroenteritis. While they often present with bloody stools, some cases can have watery diarrhea.
- Food Poisoning: This can be caused by consuming contaminated food, leading to symptoms similar to viral or bacterial gastroenteritis.
- Medication-Induced Diarrhea: Certain medications, such as antibiotics, can cause diarrhea as a side effect.
Do Not Miss Diagnoses
- Clostridioides difficile (C. diff) Infection: Although less common, C. diff can cause severe diarrhea, especially in individuals who have recently used antibiotics. Missing this diagnosis can lead to severe complications.
- Inflammatory Bowel Disease (IBD) Flare: While less likely, an initial presentation of IBD (such as Crohn's disease or ulcerative colitis) could be mistaken for gastroenteritis. Missing this diagnosis could delay appropriate treatment.
- Intestinal Parasites: Infections with parasites like Giardia can cause prolonged diarrhea and are important not to miss, especially in individuals with certain risk factors (e.g., travel history, immunocompromised state).
Rare Diagnoses
- Cholera: Caused by Vibrio cholerae, this infection is rare in developed countries but can cause severe, watery diarrhea.
- Ischemic Bowel Disease: Although rare, conditions affecting blood flow to the intestines can cause diarrhea among other symptoms.
- Hormone-Producing Tumors: Certain tumors, like VIPomas, can cause severe, watery diarrhea due to the excessive production of vasoactive intestinal peptide (VIP).