wow 16 days good job, if it's definite pain i wouldn't describe that as hunger, many fasting books describe REAL hunger as a sensation in the mouth/throat, much like thirst, and classify the other sensations as apetite. maybe your stomach is just cleansing, i'm 5 days into my Water Fast (started 8 days ago with juice) and my stomach is still cramped and tight most of the time but it doesn't feel like hunger to me, more like nausea.
take care, you can always step down to juices if you get scared