Re: How long does water take digest, if you drink it while fully hydrated?

Some water can be absorbed directly from the stomach, but most of it is released into the small intestine, where the majority of the absorption occurs. Chyme (the mix of water, food and gastric secretions) is released from the stomach at about 1-5 ml/minute. According to Shils et al. (1994), the small intestine can absorb 200-400 ml of water an hour. This rate is highly dependent on the presence of other compounds in the stomach and small intestine. For example, the more fat that is present, the slower the rate of gastric emptying and the slower the rate of water absorption.

Source: ME Shils, JA Olson, and M Shike. 1994. Modern Nutrition in Health and Disease, eighth edition.