Melanocytes are involved in what two functions of the integumentary system?
a. protection and the excretion of waste
b. the sensation of temperature and the excretion of waste
c. protection and vitamin generation
d. the sensation of temperature and vitamin generation

when you rub, you also apply pressure, that pressure can urge the poop to come out. i think that when your rubbing, you also might be slightly breaking it up and that can further fill the stomach.  

the psychologist would claim that the research results were significant.