For many years infant colic was defined as crying for >3 hours a day, for > 3 days a week, for a period of 3 weeks or longer in otherwise healthy infants.1 For various reasons this widely known and used definition was changed in 2016 to diagnostic criteria that stated that infant colic must begin and stop in an infant <5 months of age, and must show recurrent and prolonged periods of infant crying, fussing or irritability reported by caregivers that occur without obvious cause and cannot be prevented or resolved by caregivers. There should also be no evidence of infant failure to thrive, fever or illness.2 It has recently been reported 3 that Infant colic is responsible for 25% of paediatric consultations in the first 3-4 months of life and affects from 5% to 30% of infants between 2 weeks and 3 months of age.4-7
Partty and Kalliomaki succinctly reported that even after many years of research the aetiology of colic is uncertain and treatment options are limited.8 Nevertheless, there have been a number of relatively recent reviews that allow treatment options to be considered. Firstly, Harb and co-workers 9 published a systematic review in 2016 of potential interventions in breastfed infants with colic. A number of interventions were identified in the literature, including the use of probiotics, fennel based preparations, low maternal allergen diets, the use of commercially available preparations and the administration of glucose, sucrose or lactase. In more detail, a number of studies showed a reduction in crying time when compared to a placebo when Lactobacillus reuteri was given to infants. It was also reported that three studies showed crying time reduced after fennel based preparations. There were fewer studies to support the use of a low maternal allergen diet, sucrose or glucose and a single study found no difference in crying time when lactase was administered. Another review published four years later in 2020 largely confirmed the findings relating to the use of Lactobacillus reuteri for shortening crying time, with the authors stating that there was “moderately strong evidence” that the probiotic was effective.10 They also reported that based on their findings acupuncture was not an effective treatment.
Finally, in 2021 Simonson and co-workers evaluated a range of probiotics for both the treatment and prevention in both formula-fed and breastfed infants.11 They concluded that probiotics reduced crying time by at least 50% in breastfed infants and that probiotics, and especially Lactobacillus reuteri DSM 17938, could be safely recommended to parents. More data and/or further studies were needed in formula-fed infants before any recommendations could be made and no evidence was found to refute or support the use of probiotics to prevent colic. Probiotics therefore, seem to be gaining support for a treatment option in colic, at least in breastfed infants, but in a fast-moving area of research, a 2021 study found that in formula-fed infants the use of a “standard” formula containing no probiotics resulted in a reduction in crying time when compared to a partially hydrolysed formula with probiotics and reduced lactose content.3 Clearly, it will be important to evaluate new data forthcoming in the coming years.