Does constipation occur in your stomach or your intestines?

first of all constipation is not a stomach problem.secondly its an intestine problem but of large intention. and esp of colon region .where the waste product became solid because of dehydration. 

Constipation occurs in your intestines. 

It is very rare to see obstruction extending to the stomach, but when this does, one may observe fecal vomiting, which is exactly what it describes.