How did i gain 4 pounds in a day? i eat what i usually eat everyday and yesturday i weighted 123 and tkday i weighed 127 and i pooped 3 times?

Weight gain: Such a large weight gain in one day is likely related to water retention. This could be secondary to an increase salt intake like through chinese food, or fast food, or could happen with an associated menstrual cycle. Not to worry, the weight will likely come off over the next few days. As an aside, it is not necessarily the best idea to weigh yourself daily unless you want to go a little nuts.