Differential Diagnosis for Abdominal Pain

Abdominal pain can be caused by a variety of conditions, and its differential diagnosis is broad. The location of the pain can help narrow down the possible causes. Here's a structured approach to the differential diagnosis of abdominal pain, categorized for clarity:

• Single Most Likely Diagnosis
  • Appendicitis: Often presents with pain initially around the navel and then moving to the lower right abdomen. It's a common cause of acute abdominal pain, especially in younger individuals.
• Other Likely Diagnoses
  • Gastroenteritis: Inflammation of the stomach and intestines, usually due to infection, leading to abdominal pain, diarrhea, and vomiting.
  • Urinary Tract Infection (UTI): Can cause lower abdominal pain, especially in women, along with symptoms like dysuria and frequent urination.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic abdominal pain, diarrhea, and weight loss.
  • Diverticulitis: Inflammation of the diverticula in the digestive tract, often causing left lower quadrant abdominal pain.
• Do Not Miss Diagnoses
  • Ectopic Pregnancy: A pregnancy that develops outside the uterus, often presenting with severe abdominal pain and vaginal bleeding. It's a medical emergency.
  • Ruptured Aortic Aneurysm: A life-threatening condition where the aorta ruptures, causing severe abdominal and back pain.
  • Intestinal Obstruction: Blockage of the intestine, which can cause severe abdominal pain, vomiting, and constipation.
  • Pancreatitis: Inflammation of the pancreas, which can cause severe upper abdominal pain radiating to the back.
• Rare Diagnoses
  • Mesenteric Ischemia: A condition where the blood flow to the intestines is blocked, leading to severe abdominal pain out of proportion to the physical examination findings.
  • Primary Peritonitis: Infection of the peritoneum, the lining of the abdominal cavity, which can be spontaneous or secondary to another condition.
  • Ovarian Torsion: Twisting of the ovary, cutting off its blood supply, leading to severe lower abdominal pain.

Each of these diagnoses has distinct features and requires a thorough history, physical examination, and sometimes diagnostic tests to confirm. The key to managing abdominal pain effectively is to consider the broad range of possible causes and to prioritize those that are life-threatening.