The procedure to check-you-out is named Upper GI Series. Gastritis is inflammation of the
stomach lining, and can keep your
stomach in pain that surely affects your bowels and constipation. In the meantime, I can offer some suggestions to maybe work on your constipation.
Buy from a supermarket or pharmacy, two mineral-oil enemas and a regular enema. Use one mineral-oil enema at a time to judge whether it helps. If not, try the second enema.