Infantile colic is characterized by excessive crying (defined as crying that last at least 3 hours a day, for 3 days a week, for at least 3 weeks) in an otherwise healthy infant. The crying typically starts in the first few weeks of life and ends by 4-5 months of age. The condition is usually self-limited, with no long-term adverse effects; however, it may be very distressing to parents, hence, any safe and effective treatment would be desirable. Recently, it has been suggested that probiotics may offer some benefit.This is based on the results of one open randomized controlled trial. In this trial, 83 breast-fed infants with colic defined as >3 hours of crying on >3 days/week were randomly allocated to receive Lactobacillus reuteri DSM 17938 (108 colony-forming units, once daily 30 minutes after feeding) or simethicone (60 mg/day as 15 drops twice a day after feeding) for 28 days. Mothers followed a cow's milk free diet. By day 28 after randomization, mothers of infants in the probiotic group were significantly more likely than mothers of infants in the simethicone group to report a reduction from baseline in average crying time to less than 3 hours per day (95% vs. 7%). In addition, median crying times were significantly shorter in the probiotic group than in the simethicone group. No adverse effects of L. reuteri were reported.