Got my results from the barium enema test that I did and they saw that my colon is extremly long and large... Explains why I have been constipated my?

Constipation is. Common, a dilated, colon could be a sign of hirschsprung disease with lack of proper innervation. This is quite rare. Ask the family doctor if it is the cause, in the mean time, ask them to help you with diet and fiber.