In patients with Cystic fibrosis (CF) epithelial transport of chloride and sodium is disrupted in several organs such as airways, sweat glands, pancreas and intestines. Gastrointestinal symptoms are frequent but little is known about intestinal motility and function. Earlier studies using lactulose/hydrogen breath tests have found altered intestinal transit time. The method has several sources of errors and results have been questioned. This study is using a new, non invasive method to study intestinal motility patterns and transit times, Magnetic Tracking System - 1 (MTS-1).