Lower Abdominal Pain: Causes, Symptoms & When to See a Doctor

Lower abdominal pain has diverse etiologies across gastrointestinal, gynecologic, urologic, and musculoskeletal systems.

Common Causes by System

Gastrointestinal

• Gastroenteritis (viral/bacterial)
• IBS (cramping, bloating, altered bowel habits)
• Constipation, fecal impaction
• Diverticulitis (LLQ, fever, leukocytosis)
• Appendicitis (RLQ, migratory pain, anorexia, fever)
• IBD (Crohn's, ulcerative colitis)
• Obstruction (vomiting, distension, absolute constipation)

Gynecologic (Female)

• Dysmenorrhea (menstrual cramps)
• Ovarian cysts (rupture, torsion)
• Endometriosis (chronic pelvic pain, dysmenorrhea, dyspareunia)
• PID (cervical motion tenderness, fever, discharge)
• Ectopic pregnancy (RLQ/LLQ, amenorrhea, vaginal bleeding, hemodynamic instability — emergency)
• Fibroids (pressure, menorrhagia)

Urologic

• UTI (dysuria, frequency, urgency, suprapubic pain)
• Nephrolithiasis (colicky flank→groin pain, hematuria)
• Interstitial cystitis (bladder pain, urgency)

Male-Specific

• Prostatitis (perineal pain, dysuria, fever)
• Testicular torsion (acute scrotal pain — surgical emergency)
• Epididymitis

Musculoskeletal & Other

• Abdominal wall strain, hernia (inguinal, femoral, incisional)
• Referred pain (renal, cardiac, thoracic)

Red Flags → Immediate Evaluation

• Severe, acute onset
• Hemodynamic instability (hypotension, tachycardia)
• Fever + peritoneal signs (rigidity, rebound)
• Pregnancy + pain/bleeding
• Hematemesis, melena, hematochezia
• Inability to pass urine/stool

Diagnosis: history, exam, labs (CBC, BMP, LFTs, lipase, UA, β-hCG), imaging (US, CT). Treatment is etiology-specific.