What are two examples of barriers the immune system works with?

The innate immune system is composed mainly of physical barriers, such as skin and mucous membranes, chemical barriers, through the action of antimicrobial peptides and reactive oxygen species, innate immune cells, and soluble mediators such as the complement system, innate antibodies, and associated cytokines

Explanation:

is it multiple choice?

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.