Differential Diagnosis for Right Lower Quadrant (RLQ) Pain
Single Most Likely Diagnosis
- Appendicitis: This is the most common cause of RLQ pain, especially in younger individuals. The pain often starts around the navel and then moves to the RLQ. Appendicitis is an emergency that requires prompt surgical intervention.
Other Likely Diagnoses
- Ovarian Cyst or Torsion: In females, ovarian cysts can cause RLQ pain, especially if they rupture or torsion occurs. This condition requires urgent medical attention.
- Ectopic Pregnancy: Another condition in females, ectopic pregnancy can present with RLQ pain, vaginal bleeding, and is a medical emergency.
- Diverticulitis: Inflammation of the diverticula in the colon can cause RLQ pain, especially in older adults. It may be accompanied by changes in bowel habits and fever.
- Intestinal Obstruction: Obstruction of the small or large intestine can cause severe abdominal pain, including in the RLQ, along with vomiting, constipation, and abdominal distension.
Do Not Miss Diagnoses
- Ectopic Pregnancy: As mentioned, this is a medical emergency that can be fatal if not promptly diagnosed and treated.
- Ruptured Aneurysm: Although less common, a ruptured abdominal aortic aneurysm can present with abdominal pain, including in the RLQ, and is immediately life-threatening.
- Ovarian Torsion: This condition can cut off blood supply to the ovary and requires immediate surgical intervention to save the ovary.
- Mesenteric Ischemia: Reduced blood flow to the intestines can cause severe abdominal pain, including in the RLQ, and can lead to bowel infarction if not promptly treated.
Rare Diagnoses
- Meckel's Diverticulitis: Inflammation of a Meckel's diverticulum, a congenital anomaly of the small intestine, can cause RLQ pain.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease or ulcerative colitis can cause chronic abdominal pain, including in the RLQ, along with changes in bowel habits.
- Ureteral Calculi: Kidney stones passing through the ureter can cause severe pain, including in the RLQ, if the stone is in the distal ureter.
- Yersinia Enterocolitis: A bacterial infection that can cause abdominal pain, including in the RLQ, especially in children and young adults.