Differential Diagnosis for Left Lower Quadrant (LLQ) Abdominal Pain
Single Most Likely Diagnosis
- Diverticulitis: This is often the most common cause of LLQ abdominal pain in adults, especially those over 40 years old. Diverticulitis occurs when diverticula (small pouches) in the wall of the colon become inflamed. Symptoms include pain, tenderness, and guarding in the LLQ, fever, and changes in bowel habits.
Other Likely Diagnoses
- Irritable Bowel Syndrome (IBS): A common condition characterized by chronic abdominal pain, bloating, and changes in bowel movements. While it can cause pain in any quadrant, it often involves the lower quadrants.
- Constipation: Can cause significant abdominal pain and discomfort, often localized to the lower quadrants.
- Ovarian Cyst or Torsion: In females, ovarian cysts can cause LLQ pain if they rupture or torsion occurs. Symptoms can include sudden onset of severe pain, nausea, and vomiting.
- Ectopic Pregnancy: Should be considered in females of childbearing age presenting with LLQ pain, especially if there's a history of missed periods or positive pregnancy test.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic inflammation and pain in the abdomen, including the LLQ.
Do Not Miss Diagnoses
- Appendicitis: Although appendicitis typically presents with right lower quadrant pain, in some cases (especially if the appendix is retrocecal), it can cause LLQ pain. Missing this diagnosis can lead to perforation and severe complications.
- Intestinal Obstruction: Can cause severe abdominal pain, vomiting, and constipation. It requires prompt diagnosis and treatment to prevent complications like ischemia and perforation.
- Ruptured Abdominal Aortic Aneurysm: A life-threatening condition that can present with abdominal pain, back pain, and hypotension. It's more common in older adults with risk factors like smoking and hypertension.
- Pneumonia: Lower lobe pneumonia can cause referred pain to the abdomen, including the LLQ, especially if the diaphragm is involved.
Rare Diagnoses
- Endometriosis: Can cause chronic pelvic pain, including LLQ pain, especially during menstruation.
- Colonic Cancer: Although more common in older adults, it can present with abdominal pain, changes in bowel habits, and weight loss.
- Intra-abdominal Testicular Torsion: A rare condition where an undescended testicle torsions, causing severe abdominal pain.
- Splenic Infarction or Rupture: Can cause severe LLQ pain, especially if there's a history of trauma or conditions affecting the spleen like sickle cell disease.