What should I do if I have sharp lower abdominal pain?

Sharp Lower Abdominal Pain: Immediate Action Plan

Seek immediate medical evaluation in an emergency department or urgent care facility for CT imaging of the abdomen and pelvis with IV contrast, which is the gold standard diagnostic test for acute lower abdominal pain. 1, 2

Immediate Steps to Take

Go to the Emergency Department If You Have:

• Severe or worsening pain that is sharp and persistent 2, 3
• Fever (temperature >100.4°F/38°C), which suggests infection or perforation 2, 3
• Rapid heart rate (tachycardia), the most sensitive early warning sign of surgical complications 2
• Vomiting with abdominal distension, suggesting bowel obstruction 3
• Rigid abdomen or pain when you release pressure (rebound tenderness), indicating possible perforation 2, 3
• Pain out of proportion to what the doctor finds on examination, which strongly suggests mesenteric ischemia 2, 3

What Will Happen at the Emergency Department:

Mandatory Initial Testing:

• Beta-hCG pregnancy test if you are a woman of reproductive age—this is required before any imaging 2, 3
• Complete blood count to check for infection or inflammation 2
• C-reactive protein, which is more accurate than white blood cell count for detecting surgical disease 2

Imaging Decision Based on Your Pain Location:

Left Lower Quadrant (Left Side):

• CT abdomen and pelvis with IV contrast is the most useful examination, with 95% accuracy for identifying the cause 1, 2
• Most common cause is diverticulitis (inflammation of colon pouches), especially if you are over 40 years old 1
• CT detects critical findings like bowel perforation, which has surgical implications and higher mortality 1

Right Lower Quadrant (Right Side):

• CT abdomen and pelvis with IV contrast achieves 95% sensitivity and 94% specificity 1, 4
• Most common surgical cause is appendicitis, which requires urgent surgery 1, 4
• Ultrasound may be considered first only if you are a woman of reproductive age to check for gynecologic causes (ovarian cyst, ectopic pregnancy), but if unclear, CT will still be needed 1, 4

Central Lower Abdomen:

• CT abdomen and pelvis with IV contrast changes the diagnosis in 51% of cases and alters admission decisions in 25% of cases 3

Why CT with Contrast Is Critical:

CT identifies the full range of dangerous conditions:

• Appendicitis requiring emergency surgery 1, 4
• Diverticulitis with or without perforation 1
• Bowel obstruction from adhesions, hernias, or cancer 2, 3
• Colorectal cancer (causes 60% of large bowel obstructions in older adults) 4, 3
• Mesenteric ischemia (blood clot cutting off intestinal blood supply) 2, 3
• Kidney stones (though non-contrast CT is preferred if this is the primary suspicion) 1
• Gynecologic emergencies like ectopic pregnancy or ovarian torsion 1, 3

IV contrast is essential because it improves detection of bowel wall inflammation, vascular problems, and fluid collections 1

Critical Pitfalls to Avoid:

• Do not assume normal lab tests mean nothing is wrong, especially if you are elderly—serious infections can occur with normal white blood cell counts 2, 4
• Do not delay seeking care if you are over 65 years old—elderly patients have higher rates of cancer, diverticulitis, and vascular emergencies, and often present with atypical symptoms 2, 4, 3
• Do not rely on ultrasound alone if you are obese or if the appendix cannot be visualized (happens in 20-81% of cases)—you will need CT anyway 4
• Normal lactate does not exclude bowel ischemia—early ischemia can have normal labs 2

Special Considerations:

If You Are a Woman of Reproductive Age:

• Ectopic pregnancy must be ruled out first with beta-hCG testing before any imaging 2, 3
• Pelvic ultrasound (transabdominal + transvaginal) may be performed first to evaluate ovarian cysts, ovarian torsion, or pelvic inflammatory disease 1, 4
• If ultrasound is unclear, CT with contrast will still be needed 4

If You Are Over 65 Years Old:

• You have higher risk of diverticulitis, colorectal cancer, and mesenteric ischemia 2, 4, 3
• Atypical presentations are common—you may have serious disease without classic symptoms 4, 3
• CT should be performed even with normal labs because inflammatory responses are often blunted 2, 4

If You Have Had Prior Abdominal Surgery:

• Adhesive small bowel obstruction is highly likely (85% sensitivity) 4
• CT is essential to differentiate obstruction from other causes 4, 3

What NOT to Do:

• Do not wait at home if you have any of the red flag symptoms listed above 2, 3
• Do not take pain medication that might mask worsening symptoms before medical evaluation 5
• Do not eat or drink if you suspect you may need surgery—remain NPO (nothing by mouth) 4
• Do not assume it is just constipation or gas if the pain is severe, sharp, or associated with fever 3, 6

Bottom Line Algorithm:

1. Assess for red flags (fever, tachycardia, rigid abdomen, vomiting, severe pain) → If present, go to ED immediately 2, 3
2. At ED: Beta-hCG if female of reproductive age → Required before imaging 2, 3
3. CT abdomen/pelvis with IV contrast → Diagnostic test of choice for lower abdominal pain 1, 2
4. Treatment based on CT findings → Surgery for appendicitis/perforation, antibiotics for diverticulitis/infection, admission for obstruction 5