Why is the longer intestine called small and the shorter intestine called large?

The terms "small" and "large" intestine refer to the diameter of the intestines rather than their length. The small intestine, despite being longer (about 20 feet in adults), has a smaller diameter compared to the large intestine, which measures around 5 feet in length but has a larger diameter. The small intestine is primarily involved in nutrient absorption, while the large intestine focuses on water absorption and waste elimination. Thus, the naming reflects their relative widths rather than their lengths.