Differential Diagnosis for Abdominal Pain

The patient presents with abdominal pain tender to palpation to the right of the umbilicus, worsening when leaning forward and mildly alleviated when extending back. The absence of constipation, diarrhea, vomiting, and nausea helps narrow down the differential diagnoses. Here are the potential causes categorized for clarity:

• Single Most Likely Diagnosis

  • Musculoskeletal Pain: Given the pain's location and the fact that it worsens with leaning forward and improves with extending back, musculoskeletal pain, possibly from a strained muscle or ligament, is a plausible explanation. The movement-related exacerbation and alleviation are common characteristics of musculoskeletal issues.

• Other Likely Diagnoses

  • Appendicitis: Although the pain is not typically described as being directly to the right of the umbilicus in appendicitis (more commonly it starts around the umbilicus and then localizes to the right lower quadrant), the worsening pain with movement could be consistent with an inflamed appendix irritating the surrounding tissues.
  • Right Lower Lobe Pneumonia or Pleurisy: Referred pain from the right lower lobe of the lung can present as abdominal pain, especially if the diaphragm is involved. The worsening with leaning forward could be due to increased pressure on the diaphragm.
  • Gastrointestinal Issues (e.g., Intestinal Obstruction, Inflammatory Bowel Disease): While the absence of symptoms like constipation, diarrhea, vomiting, and nausea makes these less likely, they cannot be entirely ruled out without further investigation.

• Do Not Miss Diagnoses

  • Ectopic Pregnancy: Although less likely in patients without a clear history of missed periods or positive pregnancy test, ectopic pregnancy can present with abdominal pain and must be considered, especially in women of childbearing age.
  • Ovarian Torsion: This is a surgical emergency that can present with sudden onset of severe abdominal pain, often without clear gastrointestinal symptoms.
  • Ruptured Aortic Aneurysm: While more commonly presenting with back pain, a ruptured abdominal aortic aneurysm can cause abdominal pain and is a life-threatening condition that requires immediate attention.

• Rare Diagnoses

  • Pancreatitis: Typically presents with more severe pain and often radiates to the back. The absence of nausea and vomiting makes this less likely, but it cannot be ruled out without further testing.
  • Hernias (e.g., Spigelian, Lumbar): These can cause abdominal pain and may worsen with certain movements, but they are less common and usually have additional symptoms or findings on examination.

Each of these diagnoses requires careful consideration of the patient's full clinical picture, including history, physical examination, and potentially, diagnostic imaging or laboratory tests to determine the underlying cause of the abdominal pain.