Differential Diagnosis for Lower Left Quadrant Pain

The patient presents with intermittent lower left quadrant pain, accompanied by nausea, fever, and paleness. Considering these symptoms, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Diverticulitis: This condition is characterized by inflammation of the diverticula in the colon, which can cause severe abdominal pain, typically in the lower left quadrant. The presence of fever and nausea supports this diagnosis, as diverticulitis often leads to an infectious process.

• Other Likely Diagnoses

  • Constipation: Although less likely to cause fever, severe constipation can lead to significant abdominal pain, nausea, and a feeling of being unwell, which might be exacerbated by the straining during bowel movements.
  • Gastroenteritis: Inflammation of the stomach and intestines, usually due to infection, can cause abdominal pain, nausea, fever, and changes in bowel habits. The pain can be intermittent and may be localized to the lower quadrants.
  • Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic or intermittent abdominal pain, often accompanied by changes in bowel habits, fever, and systemic symptoms like pallor due to anemia.

• Do Not Miss Diagnoses

  • Appendicitis: Although appendicitis typically presents with right lower quadrant pain, it can occasionally present atypically, especially if the appendix is retrocecal. Missing appendicitis can lead to perforation and severe complications.
  • Ectopic Pregnancy: In women of childbearing age, ectopic pregnancy is a critical diagnosis to consider, as it can present with lower abdominal pain, nausea, and systemic symptoms. It is life-threatening if not promptly diagnosed and treated.
  • Intestinal Obstruction: This condition can cause severe, intermittent abdominal pain, nausea, vomiting, and fever. It requires immediate medical attention to prevent complications like bowel ischemia.

• Rare Diagnoses

  • Ovarian Torsion: A gynecological emergency that can cause severe, sudden onset of lower abdominal pain, often accompanied by nausea and vomiting. It is less common but critical to diagnose promptly.
  • Mesenteric Ischemia: A condition where there is insufficient blood flow to the intestines, which can cause severe abdominal pain out of proportion to the physical examination findings, along with nausea and fever. It is rare but has a high mortality rate if not treated promptly.
  • Colonic Volvulus: A condition where the colon twists around itself and its mesentery, cutting off the blood supply. It can cause severe abdominal pain, nausea, vomiting, and fever, and is a surgical emergency.