There is one exercise, more than any other, that can help you lose inches from you midsection in weeks, improve your digestion, increase your endurance, and strengthen your core all in one go. That exercise is called the abdominal vacuum. It's one of the fundamental exercises to learn in muscle control. In fact, many of the other abdominal controls become difficult without training the stomach vacuum first. But you NEED to train the vacuum if you want all the above benefits from a simple exercise.
Maxick used the abdominal vacuum to reach incredible levels of control, moving on to isolate his ab muscles in rows or columns however he wished in his controls. Otto Arco performed the same beneficial exercise, calling it "the rope" whenever he used it, and deemed it as an advanced exercise in muscle control. It is certainly advanced, with quite advanced benefits to boot!
The way that it benefits you is that it massages your internal organs, improving blood flow and, for the digestive system, food mobility. I would recommend that you not do this exercise on a full stomach. Consistent training in this exercise strengthens the transverse abdominal muscles, which work to keep your stomach tight and flat. So while the exercise may not remove body fat, it will leave you with a much stronger and fitter looking midsection.
With the improved blood flow to your internal organs, your vital energy will be nourished, which will improve your overall endurance. Control, endurance, strength, stability, and a fitter midsection? What more do you need to convince you? Here's how you do the stomach vacuum:
First, exhale all of the air in your lungs. Next, pull in your diaphragm as if you were going to inhale, but don't actually inhale any air. If all goes well, it should look (for better or worse) like this:
The image on the left is the exhale, and the image on the right is pulling in the diaphragm without inhaling. The side profile can be seen below.
Go ahead and try it out for yourself! You won't be disappointed with the results.