Gastrointestinal infection testing encompasses laboratory diagnostics—culture, molecular PCR, immunoassays, and rapid antigen tests—used to detect bacterial, viral, and parasitic pathogens causing acute and chronic GI illnesses. Its relevance is amplified by rising infection rates, antimicrobial‑resistance concerns, and the shift toward point‑of‑care testing. The global gastrointestinal infection testing market size reached approximately $2.9 billion in 2025, and analysts project a CAGR of 7.1% through 2033, driving the market toward $5.1 billion by the end of the forecast period. Growth outlook is underpinned by expanding molecular platforms, stricter regulatory mandates for rapid diagnostics, and heightened consumer demand for timely results. Key forces shaping the industry include the acceleration of multiplex PCR technologies, evolving health‑authority guidelines that favor early detection, and intensified competition among established diagnostics firms and emerging biotech entrants. North America remains the largest market, while Asia‑Pacific is emerging as the fastest‑growing region.