House & Stiens 1997; USA 
PEDro = 7 
RCT
N=15

Population: Age range=26-61, 9 subjects with cervical injuries, 6 with thoracic injuries, 11 with complete injuries, 4 with incomplete injuries, length of injury: 3 months to 45 years
Treatment: At each regularly scheduled bowel care session, either a 10 mg hydrogenated vegetable-oil base (HVB) or 10 mg polyethylene glycol base (PBG) suppository was inserted. 
Outcome Measures: time to flatus, flatus to stool flow, defecation period, wait until transfer cystometrogram, intracolonic pressure, colonic motor and myoelectrical activity 

1. Time to Flatus: PGB sig. less time than HVB
2. Flatus to stool flow: No sig. differences
3. Defecation Period: PGB sig. less time than HVB
4. Overall: PGB suppositories significantly decreased bowel care time

Stiens et al. 1998; USA
Downs & Black = 18
Prospective controlled trial
N=14

Population: All males; 4 with incomplete and 10 with complete injuries; Age: mean 53.4 years, mean time since injury 18.3 years; Level of injury: C3-L1
Treatment: Polyethylene glycol vs. vegetable oil based bisacodyl suppositories to initiate side-lying bowel care
Outcome Measures: Time to flatus; flatus to stool flow; defecation period; clean up; total bowel care time

1. Time to flatus: HVB=31 min, PGB=12 min (p<0.002); Defecation period: HVB=58 min, PGB=32 min (p<0.0005); Total bowel care time: HVB=102 min, PBG=51.2 min (p<0.0005)
2. The numbers of digital stimulations required for the bowel care sessions: HVB=5.0, PGB=3.2 (no significant difference, p=0.3505)
3. Use of PGB statistically improved bowel outcomes compared to HVB.

Frisbie 1997; USA
Downs & Black = 16
Prospective controlled trial
N=19

Population: Age: mean 64 years, range 41-81; 115 subject had motor complete injuries; mean time since injury: 19 years (range 3-51); 15 cervical and 4 thoracic (T1-7).
Treatment: A bisacodyl suppository based in polyethylene glycol (PEGBS) was compared with a conventional bisacodyl suppository based in hydrogenated vegetable oil (HVOBS)
Outcome Measures: Average time for complete bowel evacuation

1.   All patients experienced a shortening of bowel care time with PEGBS. Average time for bowel evacuation was 2.4 hours (range 1.0-4.5 hours) with HVOBS and 1.1 hours (range 0.3 to 1.8 hours) with PEGBS

Amir et al. 1998; USA
Downs & Black = 9
Cohort
N=7

Population: Age range=21-76yrs, injury level; C4-T12, 6 subjects with tetraplegia, 1 subject with paraplegia, length of injury range=2-25yrs
Treatment: Each subject was studied after receiving one week of therapy with one of the following four modalities: 1) two bisacodyl suppositories, 2) two glycerin suppositories, 3) one mineral oil enema and 4) one docusate sodium mini enema (Theravac SB) daily.
Outcome Measures: total colonic and segmental colonic transit times

1. The total colonic transit time was significantly reduced with docusate sodium mini-enemas.
2. There was no significant difference in total colonic between docusate sodium and mineral oil enema, and both produced significantly shorter transit times compared to bisacodyl or glycerin suppositories. 
3. Bowel evacuation time was least for docusate sodium mini-enemas.
4. In terms of difficulty with evacuation, docusate sodium scored best in symptom reduction followed by, in descending order of efficacy, mineral oil enema, bisacodyl suppositories and glycerin suppositories.

Dunn & Galka 1994; USA 
Downs & Black = 12
Case Series
N=14

Population: Age range=27-67yrs, level of injury: C5-L1, 5 subjects with tetraplegia, 9 subjects with paraplegia, length of injury range=2-38yrs
Treatment: First, subjects used bisacodyl suppositories for five bowel programs for baseline data. Second, they used a docusate sodium mini enema (Theravac SB) for the next five bowel programs. Finally, they used bisacodyl for five more bowel programs all while recording similar information in a diary log.
Outcome Measures: time of insertion of the rectal medication; time of first evacuation; time required to complete the first evacuation; other interventions used; bowel problems between bowel programs

1. 10 subjects complete all treatments. 
2.  Of these 10 subjects, the mean evacuation time was significantly reduced with Theravac SB compared to the mean times with both the bisacodyl interventions.
3. No significant difference in evacuation time between the first and second bisacodyl interventions.