The lack of change in body weight after defecation may be due to the light weight of the discharged feces, or the change in body weight is too slight to be obvious.
Generally speaking, as long as the defecation, the weight will have more or less change, normal people a day of defecation between 600 ~ 800 grams, but if there is constipation, each time the defecation discharge of feces less, lighter weight, this time the weight of the changes in the smaller, at this time weighing scales will find that before and after the defecation, the weight of the body does not have any change.
Secondly, the accuracy of the scale used in daily life is small, for the slight change in body weight, it is not obvious to show, so at this time to see the scale will find that there is no change in body weight after defecation.