To cure the syndrome, they recommend a candida cleanse diet, which includes  no sugar, white flour, yeast and cheese, based on the theory that these foods promote candida overgrowth. Unfortunately, there isn't much evidence to support the diagnosis of yeast syndrome.
By definition, a creek is a natural stream of water, normally smaller than, and often tributary to a river. Often, creek waters flow directly into Chesapeake Bay, or merge with other Bay tributaries, such as the Patapsco, the Patuxent, and the Potomac rivers.
Creek is one of Poppy's friends, a Troll of seemingly infinite wisdom and happiness. He is among the many trolls who are taken by the Bergens after Poppy ignores Branch's warning. Initially thought of as a supporting character, Creek plays a major role in the film's overall story.