Differential Diagnosis for 34-year-old Male with Diarrhea and Abdominal Symptoms
- Single most likely diagnosis:
- Viral Gastroenteritis: This is the most likely diagnosis given the acute onset of symptoms, including diarrhea, fever, chills, and abdominal cramping, without a clear source of bacterial contamination or recent antibiotic use. The symptoms worsening over a few days also align with the typical course of viral gastroenteritis.
- Other Likely diagnoses:
- Bacterial Gastroenteritis: Although less likely due to the lack of recent travel or antibiotic use, bacterial causes such as Salmonella, Shigella, or Campylobacter cannot be ruled out without further testing. The presence of fever, chills, and abdominal cramping supports this possibility.
- Food Poisoning: Given the sudden onset of symptoms, food poisoning from a contaminated food source is a consideration, although the patient denies any change in diet or recent travel.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Appendicitis: Despite a history of appendectomy, the possibility of a stump appendicitis or another abdominal condition mimicking appendicitis should be considered, especially given the abdominal cramping and fever.
- Inflammatory Bowel Disease (IBD) Flare: Although less common, an initial presentation of IBD (Crohn's disease or ulcerative colitis) could mimic acute gastroenteritis and would require prompt diagnosis and treatment to avoid complications.
- Intussusception: A rare condition where a part of the intestine slides into an adjacent part, which could present with abdominal pain, diarrhea, and fever, especially if there's a lead point like a tumor.
- Rare diagnoses:
- Giardiasis: An intestinal infection caused by the parasite Giardia lamblia, which could present with diarrhea, abdominal cramps, and fever, although it's less common in adults without a clear exposure history.
- Clostridioides difficile (C. diff) Infection: Although the patient denies recent antibiotic use, C. diff infection should be considered in any case of severe diarrhea, as it can have a severe course and requires specific treatment.
- Ischemic Bowel Disease: A condition where there's insufficient blood flow to the bowel, which could present with abdominal pain and diarrhea, although it's rare in a young adult without vascular risk factors.