According to an Iran-based randomized clinical study, the use of two types of synbiotics (Infant drop 1 containing Bifidobacterium infantis, Lactobacillus reuteri, Lactobacillus rhamnosus plus fructooligosaccharides and Infant drop 2 containing Bifidobacterium lactis BB-12 plus fructooligosaccharides) proved to effective and safe for relieving the symptoms of pediatric functional constipation. Niloufar Ghanbari et al. examined the safety and effectiveness of synbiotics in improving the signs and symptoms in infants (age less than 6 months) with functional constipation resistant to non-pharmacological therapy.

Infants who fulfilled the ROME IV criteria for infantile functional constipation were considered. These infants were randomly assigned to receive Infant Drop 1 (n = 44) or Infant Drops 2 (n = 45) for a month and were assessed on the 7th day and at the month's end. There was a noteworthy descending tendency in the responsive rate of clinical signs in both groups. But, infant drops 2 was significantly effective in improving the incidence of weekly defecation. As per the primary outcomes, the use of these synbiotics ameliorated the constipation symptoms in all the types of feeding methods after 7 days and after a month of use.

No side effects were reported. Both the synbiotics under consideration improved all the symptoms of functional constipation at the time points mentioned apart from the type of feeding method in infants aged <6 months. Also, B. lactis may play a more prominent role in these patients, given the outstanding efficacy of infant drops 2 in boosting stool frequency, the study authors concluded.