Table 1.

Study characteristics.

References	Country and number of centers	Endpoints used to define symptom improvement following therapy	Total number of patients	Gender, female %	Age (years)	Number of patients assigned to intervention	Number of patients assigned to control	Constipation criteria
1. van Dijk et al. (10)	Netherlands, one site	Treatment was considered successful if patients achieved a defecation frequency of ≥3 times per week and a fecal incontinence frequency of ≤1 time per 2 weeks, irrespective of laxatives use.	134	58/134 (43.2%)	6.9 ± 2.5 vs. 6.5 ± 2.1	67 patients; Behavior therapy.	67 patients; Standard medical care.	Patients had to meet at least 2 of 4 criteria: defecation frequency <3 times per week, fecal incontinence ≥2 times per week, passage of large amounts of stool at least once every 7–30 days (large enough to clog the toilet), or a palpable abdominal or rectal fecal mass.
2. van Engelenburg-van Lonkhuyzen et al. (11)	Netherlands, one site	The absence of functional constipation according to the 6 Rome III criteria. This meant meeting 1 or fewer of the 6 Rome III criteria, irrespective of laxatives use.	53	29/53 (55%)	5–15 years	26 patients; physiotherapy intervention plus standard medical care.	27 patients; standard medical care training.	Rome III
3. van der Plas et al. (12)	Netherlands, one site	Treatment was considered successful if the patients achieved three or more bowel movements per week and <2 soiling or encopresis episodes per month while not receiving laxatives for 4 weeks.	192	36/192 (34%)	8.0 (5–16)	98 patients; Five biofeedback training sessions plus standard medical care.	94 patients; Standard medical care: laxatives, dietary, toilet training, and maintenance of a diary of bowel habits.	They had to fulfill at least two of four criteria for pediatric constipation and were included if they had been treated medically for at least 1 month before randomization. ① stool frequency <3 per week; ② two or more soiling and/or encopresis episodes per week; ③ periodic passage of very large amounts of stool at least once every 7–30 days; or ④ a palpable abdominal or rectal mass.
4. van Summeren et al. (24)	Netherlands, 5 sites	Defined as the absence of functional constipation (Rome III).	134	82/134 (61%)	7.6 ± 3.5 years	67 patients; physiotherapy plus standard medical care.	67 patients; standard medical care.	Rome III
5. Loening-Baucke (25)	USA	Patients were considered to have recovered from chronic constipation and encopresis if they met the following criteria: ≥3 bowel movements per week and ≤2 soiling episodes per month while not receiving laxatives for 4 weeks.	41	10/41 (24.3%)	5–16 years	22 patients; biofeedback treatment plus standard medical care.	19 patients; standard medical care.	If they had ≥2 soiling episodes per week and evidence of a huge amount of fecal material in the rectal ampulla at rectal examination.
6. van Ginkel et al. (26)	Netherlands, one site	Successful treatment was defined as a defecation frequency of 3 or more per week and fewer than 1 soiling/encopresis episode per 2 weeks and no use of laxatives.	212	69/212 (33%)	5-17 years	97 patients; 2 manometry sessions plus standard medical care.	115 patients; standard medical care.	Subjects had to fulfill at least 2 of 4 following criteria: (1) stool frequency fewer than 3 per week; (2) 2 or more soiling and/or encopresis episodes per week; (3) periodic passage of very large amounts of stool every; (4) a palpable abdominal or rectal fecal mass.
7. Silva CAG et al (27)	Brasil, one site	Defecation frequency per week with laxatives allowed	72	42/72 (58%)	4–18 years	36 patients; physiotherapy plus standard medical care.	36 patients; standard medical care.	Rome III