Cystic Fibrosis and Gut Dysmotility: The Effect of Polyethylene Glycol (PEG) on Intestinal Transit

All patients will undergo intervention with taking polyethylene glycol (PEG) or Miralax (brand name) 17 grams once daily for total of 2 weeks.

Patients will ingest a Smart pill to obtain baseline motility within the GI lumen. After two weeks of therapy, the patient will repeat the motility survey and again ingest a smart pill to assess the change in motility symptoms while on therapy.