Postoperative infections in gastric and colorectal cancer surgeries significantly increase costs and hospital stays, demanding urgent attention.

• 11.8% of surgeries resulted in infections, with 2.2% classified as major.
• Major infections lead to double the hospitalization costs and triple the length of stay.

Surgeons should prioritize prevention strategies for intra-abdominal infections as key risk factors include comorbidities and prolonged operative times.

• Major surgical incision infections added the highest costs, averaging nearly $13,700 with extended stays of up to 31 days.