Methylene blue activated by 665nm laser light achieved a 5.86 log reduction in E. coli bacteria isolated from children with perforated appendicitis, demonstrating potent antimicrobial activity against organisms commonly resistant to conventional antibiotics. The photodynamic therapy approach proved effective against the polymicrobial infections found in 87% of the 30 pediatric cases studied, including Streptococcus anginosus and Pseudomonas aeruginosa. This finding addresses a critical gap in treating complicated pediatric appendicitis, where antibiotic resistance frequently complicates recovery and extends hospital stays. Photodynamic therapy represents a compelling alternative to systemic antibiotics, potentially reducing the selective pressure that drives resistance development while offering localized antimicrobial action. The approach could prove particularly valuable for intra-abdominal infections where biofilm formation and tissue penetration limit antibiotic effectiveness. However, clinical translation requires addressing practical challenges including light delivery to infected peritoneal cavities and determining optimal dosing protocols. While promising, this laboratory study using planktonic cultures may not fully reflect the complex biofilm environments present in actual infections, suggesting cautious optimism pending in-vivo validation studies.