Effect of bisacodyl and cascara on growth of aberrant crypt foci and malignant tumors in the rat colon

Review article: do stimulant laxatives damage the gut? A critical analysis of current knowledge

Stimulant laxatives are well established as first- or second-line treatments for constipation and although they have a reliable therapeutic effect, alleged safety concerns still exist, particularly with long-term use. The potential harmful effects on the gastrointestinal system (including carcinogenicity) of the long-term use of diphenylmethane [bisacodyl, sodium picosulfate (SPS)] and senna stimulant laxatives were assessed in a comprehensive review of the publications identified in literature searches performed in PubMed and Embase up to and including June 2023. We identified and reviewed 43 publications of interest. While stimulant laxatives at supratherapeutic doses have been shown to cause structural alterations to surface absorptive cells in animals and humans, these effects are reversible and not considered clinically relevant. No formal long-term studies have demonstrated morphological changes in enteric neural elements or intestinal smooth muscle with bisacodyl or SPS in humans. Furthermore, there is no convincing evidence that stimulant laxatives are associated with the development of colon cancer, and in fact, chronic constipation itself has been reported to potentially increase the risk of colon cancer, therefore, the use of stimulant laxatives might reduce this risk. Many studies suggesting a possible harmful effect from laxatives were limited by their failure to consider confounding factors such as concomitant neurological disease, metabolic disorders, and age. These findings highlight the lack of evidence for the harmful effects of laxatives on the colon, and thus, the benefits of treatment with stimulant laxatives, even in the long-term, should be reconsidered for the management of patients with constipation.

Long-term Use of Bisacodyl in Pediatric Functional Constipation Refractory to Conventional Therapy

OBJECTIVES

Standard therapy for pediatric constipation includes osmotic laxatives with stimulant laxatives use only as rescue therapy. Limited information is available on regular and long-term use of bisacodyl in pediatric population despite its common use in adult and pediatric constipation.

METHODS

Retrospective review of patients with functional constipation refractory to conventional therapy (regular use of osmotic laxatives and intermittent use of stimulant laxatives only as a rescue therapy) referred to tertiary care children's hospital (January 2007-December 2014). Patients had a bowel movement (BM) frequency of ≤2 per week and were treated with bisacodyl regularly for longer than 4 weeks. Demographic variables, bisacodyl dose and treatment duration, number of BM/week before and after treatment, side effects, and length of follow-up were recorded. Response to therapy was successful when frequency of BM increased from baseline to ≥3 BM/wk.

RESULTS

A total of 164 patients were included, 52% girls, median age 9.45 years (0.9-21 years). Bisacodyl median dose was 5 mg/day, median duration of treatment was 14 months (1-77 months) with 90% of patients taking the medication for <36 months. Median number of BM/wk doubled after initiation of bisacodyl from 2 to 4 bm/w (P < 0.001). Approximately 57% of patients had successful response. At long-term follow-up 55% of patients were successfully weaned off bisacodyl (median time of 18 months). Side effects reported in 9% of patients.

CONCLUSIONS

Bisacodyl is effective and well tolerated in the long-term treatment of pediatric functional constipation refractory to conventional therapy. Most of patients with a favorable response were successfully weaned off the medication.

Effective medical treatment strategies to help cessation of purging behaviors

OBJECTIVE

Herein we review the major medical issues involved in the "detoxing" of patients who engage in purging behaviors and the pathophysiology of why they occur.

METHODS

Given a limited evidence base of randomized controlled trials, we conducted a thorough qualitative review to identify salient literature with regard to the medical issues involved in "detoxing" patients from their purging behaviors.

RESULTS

Pseudo Bartter's Syndrome is the root cause of much of the medical difficulties which can arise when purging behaviors are abruptly discontinued. However, this is imminently treatable and even preventable with a judicious medical treatment plan which targets the increased serum aldosterone levels which would otherwise promote salt and water retention and a propensity towards severe edema formation. Effective recommendations are provided which can make this process much less vexing for patients attempting to cease their purging behaviors.

CONCLUSIONS

"Detoxing" from purging behaviors can be fraught with medical complications which frustrate these patients and can lead to unsuccessful outcomes. Medical providers should become familiar with the pathophysiology which is the basis for Pseudo Bartter's Syndrome and the effective medical treatments which can lead to a successful outcome.

Bowel movement and constipation frequencies and the risk of colorectal cancer among men in the Netherlands Cohort Study on Diet and Cancer

The authors investigated the associations between bowel movement and constipation frequencies and colorectal cancer (CRC) endpoints among men in the Netherlands Cohort Study on Diet and Cancer (n = 58,279) and explored whether dietary fiber intake may modify associations. After 13.3 years (1986-1999), 1,207 CRC cases and 1,753 subcohort members were available for case-cohort analyses. Multivariate analyses showed a significantly increased hazard ratio for CRC overall and rectal cancer in men who reported having a bowel movement 1-2 times per day (second-highest category) as compared with once a day (CRC: hazard ratio (HR) = 1.29, 95% confidence interval (CI): 1.09, 1.53 (P(trend) < 0.001); rectal cancer: HR = 1.50, 95% CI: 1.15, 1.95 (P(trend) = 0.001)). Hazard ratios for CRC overall and rectal cancer were significantly decreased and lowest in men who reported suffering from constipation sometimes or more often versus never (CRC: HR = 0.76, 95% CI: 0.58, 0.98 (P(trend) = 0.02); rectal cancer: HR = 0.57, 95% CI: 0.35, 0.90 (P(trend) = 0.01)). No trends in the associations with proximal or distal colon cancer risk were observed. Interactions with dietary fiber intake were not significant. In this study, frequent bowel movements were associated with an increased risk of rectal cancer in men, and constipation was associated with a decreased risk.

Polyethylene glycol, unique among laxatives, suppresses aberrant crypt foci, by elimination of cells

OBJECTIVE

Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcinogenesis was tested. We also investigated the PEG effects on crypt cells in vivo.

MATERIAL AND METHODS

Fischer 344 rats (n=272) were injected with the colon carcinogen, azoxymethane. They were then randomized to a standard AIN76 diet containing one of 19 laxative agents (5% w/w in most cases): PEG 8000 and other PEG-like compounds, carboxymethylcellulose, polyvinylpyrrolidone, sodium polyacrylate, calcium polycarbophil, karaya gum, psyllium, mannitol, sorbitol, lactulose, propylene glycol, magnesium hydroxide, sodium phosphate, bisacodyl, docusate, and paraffin oil. Aberrant crypt foci (ACF) and fecal values were measured blindly after a 30-day treatment regimen. Proliferation, apoptosis, and the removal of cells from crypts were studied in control and PEG-fed rats using various methods, including TUNEL and fluorescein dextran labeling.

RESULTS

PEG 8000 reduced the number of ACF 9-fold in rats (p<0.001). The other PEGs and magnesium hydroxide modestly suppressed ACF, but not the other laxatives. ACF number did not correlate with fecal weight or moisture. PEG doubled the apoptotic bodies per crypt (p<0.05), increased proliferation by 25-50% (p<0.05) and strikingly increased (>40-fold) a fecal marker of epitheliolysis in the gut (p<0.001). PEG normalized the percentage of fluorescein dextran labeled cells on the top of ACF (p<0.001).

CONCLUSIONS

Among laxatives, only PEG afforded potent chemoprevention. PEG protection was not due to increased fecal bulking, but in all likelihood to the elimination of cells from precancerous lesions.

Constipation, laxative use and risk of colorectal cancer: The Miyagi Cohort Study

The objective of this study was to investigate the association between constipation or laxative use and the risk of colorectal cancer in Japanese men and women. In 1990, we delivered a self-administered questionnaire to 41670 subjects who were 40-64 years old. During the seven years of follow-up, 251 incident cases of colorectal cancer were documented. Constipation was defined as a bowel movement frequency of less than daily. The multivariate relative risk (RR) of colorectal cancer for constipated subjects compared with those with daily bowel movements was 1.35 (95% Confidence Interval: 0.99-1.84). The RR for laxative users over non-users was 1.31 (0.88-1.95), and for frequent users (twice a week or more) it was 2.75 (1.48-5.09). When colorectal cancers were divided into colon cancers or rectal cancers, a significant association was found with colon cancer alone. Our results support the hypothesis that constipation or laxative use increases the risk of colon cancer.