Prospective study of biofeedback retraining in patients with chronic idiopathic functional constipation

Table 1 Common features of the patients

No. of cases	50 (36, female)
Average age	52.6 (10-71) years
Average history	4.6 (2.5-30) years
Average onset age	34 (1-60) years
Complaint in childhood	4
Average follow-up period	18 (12-28) months
Times of biofeedback treatment	1
Failed treatment prior to BF
Normal traditional conservative treatment	50
Operation	4

Table 2 Successful rate in patients with different types of constipation

Types	n	Successful rate (%)
Slow transit	8	3
Pelvic floor dysfunction	36	26 (72.2%)
Paradoxical puborectalis contraction	20	16 (80%)
Pelvic floor spasm syndrome	9	6 (66.7%)
Intussusception	7	4 (55.6%)
Mixed	6	2

Table 3 Symptoms Changes before and after Biofeedback (BE)

Symptoms	No. of patients before BF	No. of patients 10 days after BF	No. of patients 1 year after BF
Difficult evacuation	50	16a	13a
Hard stools	40	18b	16b
Loose stools at onset of abd. Pain	39	19 (NS)	22 (NS)
No sense of defecate in 1 week	35	20 (NS)	16 (NS)
Need for digitations	21	11 (NS)	11 (NS)
Sense of incomplete emptying	31	18 (NS)	16 (NS)
Distention or bloating	42	15b	13b
Laxative dependence	48	12 (P < 0.01)	14a
Need of enema	31	9b	9b
Perianal pain at defecation	30	16 (NS)	11 (NS)

^aP < 0.01 vs before BF,

^bP < 0.05 vs before BF.

Table 4 Changes of anorectal manometry index before and after BF

Manometry index	Volume before BF	Volume after BF	Statistic value
Anal canal (mmHg)
Average rest pressure	49.7 ± 7.7	19.4 ± 10.1	P < 0.05
Voluntary squeeze	112.5 ± 18.5	164.4 ± 40.6	NS
Rectum
Initial sense (ml)	95.4 ± 39.1	41.4 ± 19.2	P < 0.05
Maximum tolerable (ml)	195.7 ± 42.5	412.6 ± 235.3	NS
Compliance (ml/mmHg)	5.1 ± 1.5	6.3 ± 2.9	NS

Table 5 Prognostic factors (1 year after BF therapy)

Factors	Percent of success (31)	Percent of failure (19)	Statistic value
Gender
Female (36)	22 (72.8%)	14 (73.7%)	NS
Male (14)	9 (28.1%)	5 (26.3%)	NS
Methods of BF
EMG-based (30)	20 (64.5%)	10 (52.6%)	NS
Manometry-based (20)	11 (36.1%)	9 (47.3%)	NS
Types of constipation
Slow transit (8)	3	5
Pelvic floor dysfunction (36)	26 (83.9%)	10 (52.6%)	P < 0.05
Mixed (6)	2	4
Psychological state
High-level group a(25)	15 (49.43%)	10 (52.6%)	NS
low-level group a(25)	16 (51.6%)	9 (47.3%)	NS

^aLimitation to measure high and low group was half of total number.

Table 6 Symptomatic factors index of SCL-90

Factors	Before BF	After BF
Somatization	0.5	0.2
Obsessive-compulsive	0.6	0.3
Interpersonal sensitivity	0.9	0.4
Depression	0.7	0.1
Anxiety	0.8	0.2
Hostility	0.7	0.3
Padanoid ideation	0.7	0.2
Psychoticism	0.5	0.2
Photic anxiety	0.1	0.1