Background: This study explores the impact of a gluten-free diet (GFD) on regional gastrointestinal (GI) transit times in individuals with celiac disease (CD) and non-celiac gluten sensitivity (NGCS). While a GFD is established for managing CD and wheat allergy, its effects on NGCS remain controversial due to inconclusive evidence. Methods: Utilizing a wireless motility and pH capsule (WMC) to assess regional and whole gut transit, newly diagnosed CD (n=12) and NGCS (n=12) patients underwent baseline evaluations, including measurements of gastric, small bowel, and colonic transit times. Results: At baseline conditions, individuals diagnosed with CD exhibited prolonged colonic and intestinal transit times when compared to those with NGCS (p<0.05). Following a 4-week GFD, CD patients experienced significant reductions in both intestinal and colonic transit times, along with enhanced small intestine contractility. NGCS individuals showed improvements in intestinal transit time and contractility with a GFD, although the colon exhibited no discernible effect. The GFD did not significantly impact intragastric, intestinal, or colonic pH. Conclusions: This study, employing WMC for the first time, provides novel insights into the positive effects of a GFD on intestinal and colonic transit, as well as contractility, in CD patients, and to a lesser extent, in those with NGCS.