Differential Diagnosis for Abdominal Pain and Diarrhea

Given the symptoms of abdominal pain and diarrhea for 5 days, along with an elevated lipase level of 136, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Acute Pancreatitis: The elevated lipase level is a strong indicator of pancreatitis, which often presents with abdominal pain and can be associated with gastrointestinal symptoms like diarrhea. The duration of symptoms and the laboratory finding support this diagnosis.

• Other Likely Diagnoses

  • Gastroenteritis: This condition, often caused by viral or bacterial infections, can lead to abdominal pain and diarrhea. Although the elevated lipase might not be directly related, it could be a secondary effect or an unrelated finding.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic or acute abdominal pain and diarrhea. The elevated lipase could be incidental or related to pancreatitis, which can be associated with IBD.
  • Mesenteric Ischemia: Although less common, this condition can cause abdominal pain and potentially diarrhea if there's involvement of the bowel. The elevated lipase might not be directly related but could indicate pancreatic involvement.

• Do Not Miss Diagnoses

  • Appendicitis: Although the primary symptom is usually right lower quadrant pain, appendicitis can sometimes present with more generalized abdominal pain and diarrhea. It's crucial to consider this diagnosis due to the potential for severe complications if missed.
  • Intestinal Obstruction: This condition can cause abdominal pain and alterations in bowel habits, including diarrhea. It's a critical diagnosis not to miss due to the risk of bowel ischemia and necrosis.
  • Pancreatic Cancer: While less likely given the acute presentation, pancreatic cancer can cause abdominal pain and elevated lipase levels. It's essential to consider in the differential, especially in older patients or those with risk factors.

• Rare Diagnoses

  • Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause abdominal pain, diarrhea, and potentially elevated pancreatic enzymes due to the inflammatory process.
  • Whipple's Disease: A rare, systemic bacterial infection that can cause malabsorption, leading to diarrhea, abdominal pain, and potentially elevated lipase levels due to pancreatic involvement.
  • VIPoma: A rare pancreatic tumor that secretes vasoactive intestinal peptide (VIP), leading to a syndrome characterized by large-volume diarrhea, hypokalemia, and achlorhydria, which could explain the elevated lipase and gastrointestinal symptoms.