Specifically potassium and sodium.
It’s not 2 hours, clear fluids such a water or gatorade (salt containing fluids) will exit the stomach within 30 minutes or maximum 1 hr. And once in the small intestine absorption an be rapid due to the massive surface area
Whenever I start wondering about how things get absorbed, I think of the time between eating asparagus and noting a certain smell the next time I pee. Some stuff can move insanely fast through the body.
if there’s a lot of protein + complex carbs, you need to break those down mechanically and enzymatically in the stomach. if there’s fat, a whole neuroendocrine saga prompts the gallbladder to dump bile into the duodenum (part of the small intestine right after the stomach) so that fats can be broken down into fatty acids + emulsified for transport. some fats can be directly absorbed from the small intestinal villi, but they still need to spend some time in the small intestine for absorption. the same neuroendocrine response causes gastric emptying to slow down to facilitate effective absorption.
electrolytes have a very different transport mechanism with fewer steps involved. you need a bit of glucose and salt present, they enter the specific transporter together, and water follows passively. the process is driven primarily by an electrochemical gradient (although hormones are obviously involved in regulating hydration level, that’s more involved at the level of the kidneys - when blood levels drop, sodium and potassium are reabsorbed by the kidneys rather than excreted via urine)
Long answer: http://www.vivo.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_water.html
Short answer: Electrolytes get a fast pass along with some simple sugars and are part of absorbing water so fast.