Multicenter Study of Patient-reported Gastrointestinal Symptoms in People With Cystic Fibrosis

Inclusion Criteria: 1. All genders ≥ 2 years of age at time of consent 2. Documentation of a Cystic Fibrosis (CF) diagnosis as evidenced by one or more clinical features consistent with the CF phenotype and one or more of the following criteria: * Sweat chloride equal to or greater than 60 milliequivalent (mEq)/liter by quantitative pilocarpine iontophoresis test (QPIT) * Two well-characterized mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene * Abnormal nasal potential difference (NPD) (change in NPD in response to a low chloride solution and isoproterenol of less than -5 mV) 3. Enrolled in the Cystic Fibrosis Foundation Patient Registry (subjects may enroll in the Registry at Enrollment Visit if not previously enrolled) 4. Written informed consent (and assent when applicable) obtained from subject or subject's legal representative 5. Willing to complete questionnaires on mobile device 6. Able to use the Medidata Patient Cloud mobile application for completing the questionnaires Exclusion Criteria: 1. Presence of a condition or abnormality that, in the opinion of the Investigator, would complicate interpretation of study outcome data or interfere with achieving the study objectives 2. Presence of a pulmonary exacerbation at the Enrollment Visit 3. Hospitalization for distal intestinal obstruction syndrome (DIOS) within the 28 days prior to the Enrollment Visit 4. Current gastrointestinal (GI) or abdominal/pelvic malignancy 5. Abdominal or pelvic surgery within the 28 days prior to the Enrollment Visit 6. At the time of the Enrollment Visit, planned abdominal or pelvic surgery or bowel cleanout in the 28 days after the Enrollment Visit 7. Initiation of new CFTR modulator therapy within the 4 weeks prior to the Enrollment Visit 8. Intent to initiate new CFTR modulator therapy within 28 days of the Enrollment Visit