PHILADELPHIA — Celestine Tention's grandmother used to chase antacid tablets with ginger ale, one after another, day after day. Years passed before the pain was so bad that she had to get help, but by then there wasn't much doctors could do. Tention's grandmother moved from her home in Harlem to live with Tention's family, and they did their best to care for her. "We had to watch her — literally watch her — die from colon cancer," said Tention, 64, of Philadelphia. Tention thought back on her grandmother's experience when, getting older herself, she started having acid reflux. Reaching for the...