Differential Diagnosis for 3 Days of Diarrhea and Mild Diffuse Abdominal Pain

• Single Most Likely Diagnosis
  • Viral Gastroenteritis: This is the most common cause of acute diarrhea and abdominal pain, often due to norovirus or rotavirus, and typically resolves on its own within a few days.
• Other Likely Diagnoses
  • Bacterial Gastroenteritis: Caused by bacteria such as Salmonella, Shigella, or Campylobacter, which can lead to similar symptoms and may require antibiotic treatment.
  • Food Poisoning: Consuming contaminated or spoiled food can lead to diarrhea and abdominal pain, with symptoms usually appearing within hours of eating the offending food.
  • Lactose Intolerance or Other Food Intolerances: Difficulty digesting certain foods can cause chronic or acute diarrhea and abdominal pain.
• Do Not Miss Diagnoses
  • Appendicitis: Although it typically presents with more severe, localized pain, early appendicitis can manifest with diffuse abdominal pain and diarrhea, making it crucial not to miss this diagnosis due to its potential for severe complications if untreated.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic diarrhea and abdominal pain but may also have acute presentations that need to be considered to avoid delayed diagnosis and treatment.
  • Intestinal Obstruction: This is a medical emergency that can cause severe abdominal pain, vomiting, and diarrhea, especially if the obstruction is partial.
• Rare Diagnoses
  • Giardiasis: An intestinal infection caused by the parasite Giardia lamblia, which can lead to chronic diarrhea and abdominal pain but is less common in areas with good sanitation.
  • Celiac Disease: An autoimmune reaction to gluten that can cause diarrhea, abdominal pain, and malabsorption, though it's less likely to present acutely.
  • Whipple's Disease: A rare, systemic bacterial infection that can cause diarrhea, abdominal pain, and malabsorption, among other symptoms, and requires specific antibiotic treatment.