Spontaneous bacterial peritonitis (SBP) is an acute bacterial infection of the ascitic fluid, commonly occurring in patients with cirrhosis and associated with high morbidity and mortality if not promptly treated. Diagnosis is primarily confirmed by a polymorphonuclear leukocyte count of ≥250 cells/mm³ in ascitic fluid, and treatment typically involves empirical antibiotic therapy, often with third-generation cephalosporins.