What is the diagnosis for a 61-year-old male presenting with acute diarrhea (diarrhea), characterized by liquid stool transitioning to soft stool, accompanied by lower abdominal cramping discomfort, chills, and a self-reported feverish sensation that resolved, with a frequency of approximately 12 episodes over two days?

Differential Diagnosis for 61-year-old Male with Diarrhea

• Single most likely diagnosis
  • Viral Gastroenteritis: This is the most likely diagnosis given the patient's symptoms of diarrhea, chills, and feeling feverish, which are common presentations of viral gastroenteritis. The fact that the symptoms started to resolve and the diarrhea transitioned from liquid to soft stool also supports this diagnosis.
• Other Likely diagnoses
  • Bacterial Gastroenteritis: This is another possible diagnosis, as the patient's symptoms of diarrhea, abdominal cramping, and fever could be caused by a bacterial infection. However, the fact that the symptoms started to resolve without treatment makes viral gastroenteritis more likely.
  • Food Poisoning: The patient's symptoms could also be caused by food poisoning, which is usually caused by consuming contaminated food or water. However, there is no specific information about the patient's diet or exposure history that would support this diagnosis.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Clostridioides difficile (C. diff) Infection: Although less likely, C. diff infection is a serious condition that can cause severe diarrhea and colitis, especially in older adults. It is often associated with antibiotic use, but can also occur without a clear precipitant.
  • Inflammatory Bowel Disease (IBD): While less likely, IBD (e.g., Crohn's disease, ulcerative colitis) can present with similar symptoms, including diarrhea and abdominal pain. Missing this diagnosis could lead to delayed treatment and potentially severe complications.
• Rare diagnoses
  • Giardiasis: This is a rare diagnosis, but it can cause chronic diarrhea and abdominal cramping. It is usually associated with exposure to contaminated water or travel to endemic areas.
  • Intestinal Ischemia: This is a rare but serious condition that can cause abdominal pain and diarrhea. It is usually associated with atherosclerosis, embolism, or venous thrombosis, and can be life-threatening if not promptly diagnosed and treated.