Table 2. Characteristics of placebo-controlled randomized trials of probiotics / comparison in constipation in children and adolescents.

Study, year, reference	Patients		Probiotic		Comparison (n)/presentation	Duration	Allocation concealment/blind analysis/intention to treat/follow-up losses
	n (age)	Definition of constipation	Genus, species and strain (n)	Dose/presentation
Banaszkiewicz et al., 2005 18	(2-16 years old)	Less than three bowel movements/wk. for at least 12 weeks	L. rhamnosus GG ATCC 531032 + Lactulose (n=43)	2x/day 10 9 CFU/capsules	placebo + lactulose (n = 41)/capsules	26 weeks (12 weeks of treatment)	yes/yes/yes/yes
Bu et al., 2007 21	45 (1-4 years old)	Less than three bowel movements/wk. for more than two months and anal fissure with bleeding or faecal leak or hard/large stools	L. casei rhamnosus Lcr35 (n = 18)	2x/day 8 × 108 CFU/capsules	MgO (n = 18) Placebo (n = 9)/capsules	4 weeks	yes/yes/yes/yes
Coccorullo et al., 2010 16	44 (5-10 months old)	Rome III Criterion (2006) for functional constipation	Lactobacillus reuteri DSM 17938 (n = 22)	1x/day 108 CFU/oily suspension in drops	Placebo (n = 22)/oily suspension in drops	eight weeks	yes/yes/yes/yes
Tabbers et al., 2011 20	148 (3-16 years old)	Rome III Criterion (2006) for functional constipation	Bifidobacterium lactis DN-173 010 (n=74)	2x/day 4.25 x 109 CFU/fermented milk	Placebo (n=74)/Low lactose non-fermented dairy	five weeks (three weeks of treatment)	yes/yes/yes/yes
Guerra et al., 2011 22	59 (5-15 years old)	Rome III Criterion (2006) for functional constipation	Bifidobacterium longum (n = 29)	1x/day 109 CFU/goat yogurt	Placebo (n = 30)/goat yogurt	ten weeks (crossover after five weeks)	yes/yes/yes/yes
Sadeghzadeh et al., 2014 23	48 (4-12 years old)	Rome III Criterion (2006) for functional constipation	Protexin* (n = 24)	1x/day 109 CFU + lactulose/sachet	placebo + lactulose (n = 24)/sachet	four weeks	yes/yes/yes/yes
Russo et al., 2017 17	55 (4-12 years old)	Rome III Criterion (2006) for functional constipation	Probiotic Mix** + PEG 4000 (n = 27)	1 sachet/day	PEG 4000 (n = 28)/sachet	eight weeks	yes/no/yes/yes
Wojtyniak et al., 2017 19	81 (1-4 years old)	Rome III Criterion (2006) for functional constipation	Lactobacillus casei rhamnosus Lcr35 (n=46)	2x/day 8 × 10 8 CFU/capsules	Placebo (n = 48)/capsules	four weeks	yes/yes/yes/yes

CFU: colony forming units; PEG: polyethylene glycol (0.4 to 0.8 g/kg/day); MgO: magnesium oxide (50 mg/kg/day); lactulose (1 ­mL/­kg/­day); ^*Protexin^®: Lactobacillus casei PXN 37, Lactobacillus rhamnosus PXN 54, Streptococcus thermophiles PXN 66, Brief bifidobacterium PXN 25, Lactobacillus acidophilus PXN 35, Bifidobacterium infantis PXN 27 and Lactobacillus bulgaricus PXN 39; ^**probiotic mix: Brief bifidobacterium M-16 V^®, Infant Bifidobacterium M-63^® and Bifidobacterium longum BB536^®.