Sacral Neuromodulation as Treatment for Chronic Constipation

Change in number of bowel movements/week

(significance level P\<0.05 comparing before and after).

Change in symptoms using the questionnaire PAC-SYM

The PAC-SYM questionnaire is a 12-item questionnaire that evaluates the severity of symptoms of constipation in 3 domains (stool, rectal, and abdominal symptoms) on a 5-point Likert scale ranging from 0 (absent) to 4 (very severe). Each domain score is the mean of the non-missing items for that domain. The total score is the mean of all non-missing items (ie, symptoms). The range of the domain or total score is 0 (response is 'absent' for each item) to 4 (response is 'very severe' for each item). A negative change from baseline indicates improvement, a positive change indicates worsening of symptoms. The minimum important difference indicating clinically significant improvement is minus 0.6 (Saito \& Camilleri, 2018)

Change in symptoms using the questionnaire PAC-SYM

The PAC-SYM questionnaire is a 12-item questionnaire that evaluates the severity of symptoms of constipation in 3 domains (stool, rectal, and abdominal symptoms) on a 5-point Likert scale ranging from 0 (absent) to 4 (very severe). Each domain score is the mean of the non-missing items for that domain. The total score is the mean of all non-missing items (ie, symptoms). The range of the domain or total score is 0 (response is 'absent' for each item) to 4 (response is 'very severe' for each item). A negative change from baseline indicates improvement, a positive change indicates worsening of symptoms. The minimum important difference indicating clinically significant improvement is minus 0.6 (Saito \& Camilleri, 2018)

Change in quality of life assessed by questionnaire PAC-QOL

The PAC-QOL scale is a 28-item self-report instrument designed to evaluate the burden of constipation on patients' everyday functioning and well-being. Each item is rated on a 5-point Likert scale ranging from 0 (not at all) to 4 (extremely). The instrument can be used to generate an overall score, but is also reported to assess 4 specific constipation-related domains including: 1) Worries and concerns (11 items), 2) Physical discomfort (4 items), 3) Psychosocial discomfort (8 items), and 4) Satisfaction (5 items). Each domain score is the mean of the non-missing items for that domain. The total score is the mean of all non-missing items. The range of the domain or total score is 0 (response is 'not at all' for each item) to 4 (response is 'extremely' for each item). A negative change from baseline indicates improvement, a positive change indicates worsening of symptoms. The minimum difference indicating clinically significant improvement is -0.5 (Marquis et al., 2005)

Change in quality of life assessed by questionnaire PAC-QOL

The PAC-QOL scale is a 28-item self-report instrument designed to evaluate the burden of constipation on patients' everyday functioning and well-being. Each item is rated on a 5-point Likert scale ranging from 0 (not at all) to 4 (extremely). The instrument can be used to generate an overall score, but is also reported to assess 4 specific constipation-related domains including: 1) Worries and concerns (11 items), 2) Physical discomfort (4 items), 3) Psychosocial discomfort (8 items), and 4) Satisfaction (5 items). Each domain score is the mean of the non-missing items for that domain. The total score is the mean of all non-missing items. The range of the domain or total score is 0 (response is 'not at all' for each item) to 4 (response is 'extremely' for each item). A negative change from baseline indicates improvement, a positive change indicates worsening of symptoms. The minimum difference indicating clinically significant improvement is -0.5 (Marquis et al., 2005)