“I’ve never seen my belly so big,” said Christina, puffing her cheeks out like a cartoon character. “It keeps bloating and bloating.” Christina, the wife of my good friend Norman, was a healthy 50-year-old who took no medications and had no chronic health issues. She had first told me about the bloating, diarrhea and stomach cramps one month earlier. The symptoms had been plaguing her for weeks. Because it’s unwise to treat friends and relatives, I had refe…