Differential Diagnosis for Abdominal Pain

Abdominal pain is a common symptom with a wide range of possible causes. The differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis
  • Gastroenteritis: This is often the most common cause of abdominal pain, especially if the pain is accompanied by symptoms like diarrhea, vomiting, and fever. The justification for this being the single most likely diagnosis is its high prevalence and the fact that it can affect anyone, regardless of age or health status.
• Other Likely Diagnoses
  • Irritable Bowel Syndrome (IBS): A chronic condition characterized by abdominal pain, bloating, and changes in bowel movements. It's a common cause of chronic abdominal pain.
  • Urinary Tract Infection (UTI): Can cause abdominal pain, especially in the lower abdomen, and is often accompanied by dysuria and frequent urination.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic abdominal pain, diarrhea, weight loss, and sometimes blood in the stool.
  • Constipation: Can cause significant abdominal pain and discomfort, often accompanied by bloating and difficulty passing stools.
• Do Not Miss Diagnoses
  • Appendicitis: Although not the most common cause, appendicitis is a medical emergency that requires prompt surgical intervention. It typically presents with severe abdominal pain that initially might be diffuse but often localizes to the right lower quadrant.
  • Ectopic Pregnancy: A life-threatening condition in pregnant women that can cause abdominal pain, often accompanied by vaginal bleeding and missed periods.
  • Ruptured Aortic Aneurysm: A medical emergency that can cause severe abdominal pain and is often accompanied by back pain and hypotension.
  • Intestinal Obstruction: Can cause severe abdominal pain, vomiting, and constipation, and requires immediate medical attention.
• Rare Diagnoses
  • Porphyria: A group of disorders that can cause severe abdominal pain, among other symptoms like neurological issues and psychiatric disturbances.
  • Lead Poisoning: Can cause abdominal pain, constipation, and a range of neurological symptoms.
  • Henoch-Schönlein Purpura (HSP): A form of vasculitis that can cause abdominal pain, purpura, and sometimes kidney involvement.
  • Abdominal Migraine: A condition that causes recurrent episodes of severe abdominal pain, often accompanied by other migraine symptoms like headache and nausea.

Each of these diagnoses has a distinct set of characteristics and accompanying symptoms that can help guide the diagnostic process. A thorough history, physical examination, and appropriate diagnostic tests are crucial for determining the underlying cause of abdominal pain.