Clinical characteristics and treatment of infantile lactose intolerance and evaluation of the diagnostic value of fecal pH

Objective To investigate the clinical characteristics, diagnostic approach, and treatment of infantile lactose intolerance, and to evaluate the diagnostic value of fecal pH. Methods The feces and clinical data of all infants(less than 1 year old) diagnosed with simple diarrhea but without signs of infection were collected, who were treated at 4 Grade Ⅲ-Class-A hospitals within the period of June 2012 to June 2015 in Beijing were collected.Lactose intolerance was diagnosed based on urine galactose level, lactose tolerance test, and fecal pH.The clinical characteristics, therapeutic effects and detection methods of lactose tolerance group and intolerance group were analyzed.Then the diagnostic value of fecal pH was evaluated. Results A total of 217 infants were enrolled in the study, consisting of 113 boys and 104 girls.Their age ranged from 3 to 330 days, 174 infants (80.2%) were less than 6 months old.Among them, 156 infants were diagnosed with lactose intolerance (71.9%), their median age 90.0 days (3-330 days), while the median age of the lactose tolerant group was 51.5 days (3-300 days). The incidence of lactose intolerance in infants less than 6 months old was 70.6%, and 76.7% in those older than 6 months.Clinical characteristics showed that more infants in the lactose intolerant group were breastfed compared with the lactose tolerant group [73/156 cases(46.8%) vs.16/61 cases(26.2%), χ2=7.666, P 6 months, between the breastfeeding group and formula-feeding group, or between those with infection and those without infection (all P>0.05). Conclusions Infants with lactose intolerance often manifest foamy feces and tend to be breastfed.Lactose-free treatment efficacy was better than that with lactase.Clinical symptoms when combined with urine galactose level and lactose tolerance test can help diagnosis.However, the decrease of fecal pH proves to be unhelpful in aiding diagnosis. Key words: Lactose intolerance; Clinical characteristics; Treatment; Fecal pH