Table 1.

Study characteristics

Study	Study design	Comparator	N	Patients	Constipation definition and duration	Lactitol form	Dosing schedule	Mean dosage	Treatment duration (days)
Delas et al15	Single arm	None	114	Mean age (years): 52 Females: 76% Mean BMI: –	Constipation, <3 BMs per week; duration >1 year	Sachets	20 g for first 4 days; 10, 20, or 30 g thereafter	21 g	49
Doffoel et al16	RCT Crossover	Lactulose	60	Mean age (years): 79 Females: 87% Mean BMI: –	Chronic functional constipation requiring laxative therapy, ≤3 BMs per week; duration >2 years	Powder	15 g starting dose; 15–30 g thereafter based on response	20 g	12
Doffoel et al17	Single arm	None	14	Mean age (years): 82 Females: 86% Mean BMI: –	Chronic functional constipation requiring laxative therapy; duration > 2 years	Powder, diluted in beverage	10 g starting dose; 10–20 g thereafter based on response	14 g	156
Goovaerts and Ravelli18	Single arm	None	141	Mean age (years): 48 Females: 71% Mean BMI: –	Functional constipation; duration >3 weeks	Sachets, diluted in beverage or sprinkled on food	20 g in week 1; 10, 20, or 30 g thereafter based on response	21 g	21
Hammer and Ravelli19	RCT Parallel	Lactulose	61	Mean age (years): 54 Females: 81% Mean BMI: 23 kg/m2	Chronic functional constipation, irritable colon, or psychological conditions attributable to constipation, ≤3 BMs per week without taking laxatives; duration not reported	Sachets	20 g for first 3 days; 10 g thereafter	11 g	28
Heitland and Mauersberger20	RCT Parallel	Lactulose	60	Mean age (years): 55 Females: 37% Mean BMI: 25 kg/m2	Chronic constipation, requiring the use of laxatives; duration 5.6 years (mean)	Powder	20 g starting dose; 10, 20, or 30 g thereafter based on response	20 g	14
Ravelli et al21	Single arm	None	13	Mean age (years): 40 Females: 100% Mean BMI: 24 kg/m2	Chronic constipation, ≤3 BMs per week without taking laxatives; duration not reported	Sachets, diluted in beverage or sprinkled on food	20 g starting dose; 10, 20, 30, or 40 g thereafter based on response	20 g	28
Vanderdonckt et al22	RCT Crossover	Placebo	46	Mean age (years): 84 Females: 65% Mean BMI: 23 kg/m2	Chronic functional constipation; ≤3 BMs per week when abstaining from laxatives, with stools that are generally hard to pass; duration ≥6 months	Sachets, diluted in beverage	20 g in week 1 or week 2; 10, 20, or 30 g thereafter based on response	35 g	28
Vanderdonckt and Ravelli23	NCT* Crossover	Stimulant laxatives	10	Mean age (years): 75 Females: 30% Mean BMI: 20 kg/m2	Chronic functional constipation; stimulant laxative use ≥3 times per week; duration ≥6 months	Sachets, diluted in beverage or sprinkled on food	40 g in week 1; 20, 30, or 40 g thereafter based on response	35 g	28
Walder et al24	Single arm	None	15	Mean age (years): 37 Females: 100% Mean BMI: –	Chronic constipation, straining during >25% BMs and/or <3 BMs per week without taking laxatives; duration not reported	NR	0.2 g/kg for first 2 days; dose increased by 0.1 g/kg every 2 days until a BM within 5 hours of administration	0.3 g/kg	15**
Xu et al25	RCT Parallel	Lactulose	129	Mean age (years): 42 Females: 71% Mean BMI: –	Constipation, <3 BMs per week; duration >3 days	Powder, diluted in beverage	20 g on day 1, 5–10 g thereafter based on response	NR	7

Notes:

^*Stimulant laxatives for 2 weeks followed by lactitol for 4 weeks;

^**does not include dose-adjustment period.

Abbreviations: BM, bowel movement; BMI, body mass index; NCT, nonrandomized controlled trial; NR, not reported; RCT, randomized controlled trial.