Differential Diagnosis for 35-year-old Male with Gastrointestinal Symptoms
- Single most likely diagnosis:
- Viral Gastroenteritis: This is the most likely diagnosis given the patient's symptoms of diarrhea, decreased appetite, fatigue, nausea, headache, and low-grade temperature. The fact that he has been tolerating liquids and showed initial improvement before symptoms recurred after introducing a potentially irritating food (tomato sauce) supports this diagnosis. Viral gastroenteritis is common and often self-limiting.
- Other Likely diagnoses:
- Food Poisoning: Although the patient denies a change in diet or travel, the recurrence of symptoms after consuming tomato sauce could suggest food poisoning, possibly from a bacterial or viral contaminant in the food.
- Irritable Bowel Syndrome (IBS): The patient's symptoms could also be consistent with an exacerbation of IBS, especially if the introduction of tomato sauce triggered symptoms. However, the acute onset and presence of fever make this less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Appendicitis: Although less likely given the patient's symptoms of diarrhea and the absence of severe abdominal pain, appendicitis can present atypically and must be considered, especially if the patient's condition worsens or if abdominal pain becomes more pronounced.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can present with similar symptoms and are important to rule out, especially if symptoms persist or worsen over time.
- Infectious Colitis (e.g., Clostridioides difficile): Despite the patient's denial of antibiotic use, it's essential to consider infectious colitis, especially if symptoms worsen or if there's a possibility of undisclosed antibiotic use.
- Rare diagnoses:
- Giardiasis: An intestinal infection caused by the parasite Giardia lamblia, which could explain the patient's gastrointestinal symptoms. However, this is less likely without a history of travel or exposure to contaminated water.
- Lactose Intolerance or Other Food Intolerances: While less likely given the acute presentation, these conditions could contribute to some of the patient's symptoms, especially if certain foods trigger them.