Role of Carbon Dioxide-Releasing Suppositories in the Treatment of Chronic Functional Constipation

Abstract and Introduction

Objective: Treatment of chronic functional constipation is difficult. Both oral and topical laxatives may fail to adequately relieve symptoms, and there is risk of adverse effects such as functional or structural changes in the intestine, together with electrolyte disturbances. The aim of this study was to evaluate the efficacy and safety of a suppository that combines sodium bicarbonate and potassium bitartrate in a polyethylene glycol base to generate approximately 175mL of carbon dioxide (CO₂). This release distends the rectal ampulla, thereby stimulating peristalsis and a subsequent bowel movement.
Patients and Methods: This was a prospective, crossover, double-blind, randomised, placebo-controlled, sequential study of outpatients with chronic functional constipation. Each patient received two suppositories of identical appearance, containing active drug or placebo. The sequence of active drug-placebo (sequence 1) or placebo-active drug (sequence 2) was randomised in groups of eight. The second suppository was taken 7 days after the first. The following parameters were evaluated and scored: evacuation time, type of evacuation, feeling of emptying of the rectal ampulla, stool characteristics, anal complaints, abdominal pain and overall patient assessment.
Results: A total of 29 patients entered the study. According to a restricted sequential plan, a statistical significance (p < 0.05) in favour of the active drug was reached after 26 patients. A positive response within 30 minutes of introduction of the suppository occurred in 51.7% and 6.9% of patients treated with the active drug and placebo, respectively (p = 0.0003). Normal evacuation occurred in 65.5% and 24.1% of patients treated with the active drug and placebo, respectively (p = 0.004). Normal stool consistency was found in 44.8% and 7.2% of patients treated with the active drug and placebo, respectively (p = 0.04). Patient assessment of treatment as satisfactory occurred in 51.7% and 20.7% of subjects treated with the active drug and placebo, respectively (p = 0.029). Only a trend in favour of the active drug was observed with regard to feeling of incomplete evacuation, and active drug was comparable to placebo with regard to anal and abdominal tolerability
Conclusion: The CO₂-releasing suppository may represent an alternative to rectal laxatives for the relief of chronic functional constipation. The data obtained in this study indicate that CO₂-releasing suppositories may be usefully and safely employed in the treatment of patients at risk for electrolyte disorders such as the elderly or patients with renal or cardiovascular disorders.

Treatment of chronic functional constipation is a difficult challenge. In more severe forms of the condition, both bulking agents and oral laxatives may fail to adequately relieve symptoms, while introducing the risk of adverse effects such as abdominal pain, functional or structural changes in the intestine (increased apoptosis of colonic epithelial cells), electrolyte disturbances and abdominal distension.^[1]

The combination of oral and rectal laxatives such as stimulating suppositories, hyperosmolar enemas and faecal softening agents may contribute to satisfactory emptying of the rectum by reducing straining at stool. The results are, however, unpredictable^[2] and there is evidence that stimulating suppositories and hyperosmolar enemas are not as completely harmless as they have been believed to be.^[3]

The present investigation was carried out to evaluate the efficacy and safety of a suppository that combines sodium bicarbonate and potassium bitartrate, in a polyethylene glycol base, to generate approximately 175mL of carbon dioxide (CO₂).^[4,5] This release distends the rectal ampulla, thereby stimulating peristalsis and a subsequent bowel movement, usually within 30 minutes of introduction.

Clin Drug Invest. 2005;25(8):499-505. © 2005 Adis Data Information BV

Cite this: Role of Carbon Dioxide-Releasing Suppositories in the Treatment of Chronic Functional Constipation - Medscape - Aug 01, 2005.