Why do you think stomach cells are replaced roughly every 2 days but your red blood cells are replaced roughly every 120 days?

Stomach cells are replaced every 2 days primarily due to the harsh acidic environment and constant mechanical stress they endure while processing food, which leads to rapid wear and tear. In contrast, red blood cells have a longer lifespan of about 120 days as they serve a stable function in transporting oxygen throughout the body and do not face the same level of damage. The different rates of replacement reflect the specific functional demands and environments of these cell types.