Crying infancy is frequent and may be linked to gastroesophageal reflux disease (GERD) and/or non-IgE-mediated cow’s milk protein allergy (CMPA). The purpose of this study was to record upper gastrointestinal motility events in infants with CMPA and compare them to results in infants with functional GERD. Infants aged 2 to 26 weeks with continuous crying, GERD symptoms, and a suspected case of CMPA were included in the study. A 48-hour cry-fuss chart and a validated reflux questionnaire were used to document symptoms. To diagnose CMPA, infants were subjected to a blindfolded milk elimination-challenge sequence. GERD parameters and mucosal integrity were evaluated by 24-hour pH-impedance monitoring before and after the removal of cow’s milk protein (CMP). Gastric emptying dynamics, dual-sugar intestinal permeability, fecal calprotectin, and serum vitamin D were all assessed by 13C-octanoate breath testing. Fifty babies were enrolled in the program. Based on CMP elimination-challenge results, 14 babies were classified as having non-IgE-mediated CMPA, and 17 were not allergic to milk; 12 infants with ambiguous results and 7 with incomplete data were removed. There were no changes in GERD parameters between babies who received CMPA and those who did not. CMP removal led to a substantial reduction in reflux symptoms, esophageal acid exposure, acid clearance time, and an increase in esophageal mucosal impedance in the CMPA group.

Upper gastrointestinal motility measures did not consistently discriminate between non-IgE-mediated CMPA and functional GERD in babies with persistent crying. Elimination of CMP substantially improved GERD symptoms, esophageal peristaltic function, and mucosal integrity in the group with non-IgE-mediated CMPA.