Differential Diagnosis for Sudden Onset Diarrhea with Recent Antibiotic Use
- Single Most Likely Diagnosis
- Clostridioides difficile (C. diff) infection: This is the most likely diagnosis given the recent antibiotic use, which can disrupt the normal gut flora and lead to an overgrowth of C. diff, causing diarrhea.
- Other Likely Diagnoses
- Antibiotic-associated diarrhea: Many antibiotics can cause diarrhea as a side effect, and this could be a direct result of the recent antibiotic use.
- Viral gastroenteritis: Although less directly linked to antibiotic use, viral gastroenteritis is a common cause of sudden onset diarrhea and could be considered, especially if the patient has been exposed to someone with similar symptoms.
- Food poisoning: If the patient has recently consumed contaminated food, this could also lead to sudden onset diarrhea, regardless of antibiotic use.
- Do Not Miss Diagnoses
- Inflammatory bowel disease (IBD) flare: While less common, a flare of IBD (such as Crohn's disease or ulcerative colitis) could be triggered by antibiotic use and must be considered to avoid missing a potentially serious condition.
- Toxic megacolon: A complication of severe diarrhea (potentially from C. diff or IBD), toxic megacolon is life-threatening and requires immediate medical attention.
- Rare Diagnoses
- Small intestine bacterial overgrowth (SIBO): Although less common and not as directly linked to recent antibiotic use, SIBO could be considered in the differential diagnosis, especially if other causes are ruled out.
- Parasitic infections: Certain parasitic infections can cause diarrhea, and while rare in many areas, they should be considered, especially in patients who have traveled to endemic areas or have specific risk factors.