Sister Has Been Diagnosed With Gastric Ulcer And Polyneuropathy. She's

Sister has been diagnosed with gastric ulcer and polyneuropathy. She's lost lots of weight and can't keep food down. Also she picked up a candida organism. She is in a lot of pain and has a hard time walking. She was healthy all summer swimming every day and walking. What would cause this sudden decline in health in one month. She gas gone through gastric bypass surgery 10 years ago and it wasn't a success. Is there any help for her?