Reduction in Bowel Program Duration With Polyethylene Glycol Based Bisacodyl Suppositories Con't Steven J. Stiens. MD Time Intervals and Events of the Bowel Program 

IntervalsTime to Flatus to Defecation Wait Until INTERVALS Flatus Stool Flow Period Transfer I I I I I Suppository First Begin End Transfer EVENTS Insertion Flatus Stool Flow Stool Flow Off Toilet 

Fig 1-BP events separate the total period into discrete intervals. The BP begins with suppository insertion. First Flatus ends the interval Time to Flatus (suppository insertion until first gas is passed). Begin Stool Flow ends the second interval termed Flatus to Stool Flow and begins the Defecation Period. End Stool Flow represents the time when Defecation Period has immediately ceased. The time of Transfer off the Toilet ends the Wait Until Transfer period that represents the time spent to insure that the BP is over. The time of Transfer Off the Toilet ends the BP. 

muscle tone without voluntary contraction. Rectal examination showed increased sphincter tone without sensation, voluntary contraction, or relaxation. The seated upright bowel program had been the same for the last 8 years on a once every third day schedule with two (HVB) bisacodyl suppositories. There was no change in diet or medication during the study period. 

The two types of bisacodyl suppositories used in the study differed only in the base used for dispersion of the active ingredient. The HVB suppositories^a contained 10mg bisacodyl United States Pharmacopeia (USP) in a hydrogenated vegetable oil base. The PGB^b suppositories contained 10mg bisacodyl dissolved in a mixed polyethylene glycol polymer base of two molecular weights: E1450 and E400. 

Each bowel program was performed by the subject on a once every third day schedule with the same technique. During a 4-month period, typical BPs were selected for randomzation to two HVB or two PGB 10mg bisacodyl suppositories. At the time of each bowel program, either two P08 or two HVB bisacodyl suppositories were inserted and positioned against the mucosal surface of the distal rectum. The presence or absence of stool in the rectal vault was recorded. The time of insertion was considered time zero and the progress of the bowel program was documented with time parameters (fig I). A single subject design⁷ was used to compare parameters of the BP. 

Bowel program events were used to separate the total BP period into discrete intervals: First Flatus (ends the interval from suppository insertion until the first gas is passed), Begin Stool Flow (marks the beginning of the defecation interval), End Stool Flow (marks the end of defecation), and Time Off Toilet (marks the end of the period of waiting after stool flow has ended, the subjective end of the BP). Digital stimulations were performed in a circular motion with a gloved lubricated index finger in attempt to dilate the external and internal anal sphincters and the distal rectum stimulating reflex peristalsis. Digital stimulations were per formed if stool flow stopped or slowed in the evacuation process (approximately every 10 minutes).

 The number of digital stimulations required for each BP was recorded. Digital examination of the rectal vault followed the end of stool flow to assure complete evacuation. The amount of stool produced with each BP was recorded using the following ordinal scale: (0) none, no stool expelled; (1) small, covers less than the bottom of the toilet; (2) moderate, covers the bottom of the toilet; or (3) large, breaks the toilet water surface. Mucus and stool incontinences were recorded if they occurred between bowel programs. 

Statistical Analysis. Continuous mean interval data were compared using Wilcoxon's rank sum tests.⁸ Ordinal data were compared with Fisher's exact test.⁸ Probability (p) values were derived taking .05 as the level of signiticance. 

RESULTS 

Twenty-six discrete BPs were studied: 13 using HVB and 13 using PGB. On each suppository insertion, stool was consistently palpated in the rectal vault. At the time of the beginning of stool flow the PGB suppositories were frequently observed as only slightly reduced in size suggesting incomplete dissolution. The HVB suppositories were consistently melted by the time of stool flow. There were no bowel or mucus incontinencies between BPs. There were no com plaints of abdominal cramping or variation in stool consistency. 

All the intervals compared between the HVB and the PGB groups showed significant differences, with the exception of Flatus to Stool Flow (fig 2). Wilcoxon's rank sum tests⁸ were calculated to compare mean times in minutes for each interval of the Bps performed with HVB and PGB. The means and p values obtained were as follows: Time to Flatus (suppository insertion time until first gas expulsion) HVB 37 minutes, PGB 10 minutes, p < .0001, Flatus to Stool Flow HVB 6.0 minutes, PGB 5.9 minutes. p = .9578, and the Defecation Period HVB 31 minutes, PGB 21 minutes, p = .0043. The Total Time for the BPs (from insertion of suppository until transferring off the toilet) averaged 85 minutes for HVB, and 46 minutes for PGB, a statistically significant (p < .0001) difference. 

The numbers of digital stimulations required for the BPs were averaged (HVB 5.3, PGB 4.6) and compared using the Wilcoxon scores (rank sums) test. The observed difference did not reach significance (p = .1840). Each BP produced some stool results. The amount of stool produced by the BPs with HVB and POB. treated as discrete variables with a two-tailed Fisher's exact test, did not show a significant difference (p = .861). 

DISCUSSION 

This single-subject study investigated the statistical and clinical significance of the use of PGB bisacodyl suppositories versus the use of HVB bisacodyl suppositories using idiographic technique and found Comparable bowel program effectiveness with a reduction in BP time by approximately half using the PGB. These time differences were observed with similar volumes of stool results and without stool incontinencies. These improvements show a clinically significant result for this subject.