Can human being withstand stomach acid if they are inside?

I had this imagination. For human being can able to withstand human acid inside the stomach. Is it our stomach very corrosive. If in future there an technology able to shrink a any material include living thing to an 4 or 5 cm. As doctor they can carry out for their operation more efficiently like no other. But that is my imagination. Just to ask from your opinion. I believe if there such an unique device the doctor must have latex suite with them to do that operation. What if the doctor without latex suite and just go inside of human stomach with just oxygen breathing. What will happen?