Differential Diagnosis for Left Lower Quadrant (LLQ) Abdominal Pain
Single Most Likely Diagnosis
- Diverticulitis: This is a common cause of LLQ pain, especially in older adults. The pain is usually constant and accompanied by changes in bowel habits, fever, and tenderness in the LLQ.
Other Likely Diagnoses
- Irritable Bowel Syndrome (IBS): IBS can cause recurrent abdominal pain, often in the LLQ, accompanied by changes in bowel habits, bloating, and gas.
- Constipation: Severe constipation can cause significant LLQ pain, especially if there is a large fecal impaction.
- Ovarian Cyst or Torsion: In females, ovarian cysts or torsion can cause severe LLQ pain, often accompanied by nausea, vomiting, and fever.
- Kidney Stone: A kidney stone in the left ureter can cause severe LLQ pain, radiating to the groin, accompanied by nausea, vomiting, and hematuria.
Do Not Miss Diagnoses
- Appendicitis (if appendix is in a retrocecal position): Although appendicitis typically presents with right lower quadrant pain, a retrocecal appendix can cause LLQ pain. Missing this diagnosis can lead to perforation and peritonitis.
- Ectopic Pregnancy: In females of childbearing age, ectopic pregnancy can cause severe LLQ pain, vaginal bleeding, and syncope. Missing this diagnosis can be life-threatening.
- Inflammatory Bowel Disease (IBD): Crohn's disease or ulcerative colitis can cause chronic LLQ pain, diarrhea, weight loss, and fever. Missing this diagnosis can lead to complications like bowel obstruction or toxic megacolon.
- Sigmoid Volvulus: A sigmoid volvulus can cause severe LLQ pain, abdominal distension, and constipation. Missing this diagnosis can lead to bowel ischemia and perforation.
Rare Diagnoses
- Intussusception: A rare cause of LLQ pain, intussusception occurs when a portion of the intestine telescopes into another portion, causing bowel obstruction and ischemia.
- Colonic Cancer: Although rare in younger adults, colonic cancer can cause LLQ pain, changes in bowel habits, and weight loss.
- Endometriosis: In females, endometriosis can cause chronic LLQ pain, dysmenorrhea, and dyspareunia.
- Intra-abdominal Testicular Torsion: A rare cause of LLQ pain in males, intra-abdominal testicular torsion can cause severe pain, nausea, and vomiting.