The Effectiveness of Caffeine in Reducing Constipation in Adults: A Systematic Review

Area of Science:

• Gastroenterology
• Pharmacology

Background:

• Constipation affects 14% globally, characterized by infrequent stools or difficult passage.
• Caffeine is hypothesized to stimulate colonic motility, potentially acting as a laxative.
• Existing research on caffeine's laxative effect presents conflicting outcomes.

Purpose of the Study:

• To systematically review and assess the effectiveness of caffeine in alleviating constipation among adults.
• To synthesize findings from existing literature regarding caffeine's impact on bowel regularity.

Main Methods:

• A comprehensive literature search was conducted across multiple databases (Cochrane Library, MEDLINE, EMBASE, etc.).
• Search terms included "constipation," "faecal impaction," and "caffeine" in various forms.
• Eight studies were included, with risk of bias assessed using ROBINS-I and other tools.

Main Results:

• Studies examined caffeine from coffee, tea, energy drinks, cocoa, and kombucha.
• Four studies suggested potential effectiveness of caffeine for constipation relief.
• Four studies indicated no improvement or an exacerbation of constipation symptoms.
• Meta-analysis was not feasible due to heterogeneity in interventions and outcome measures.

Conclusions:

• The current evidence on caffeine's effectiveness for constipation is contradictory.
• Further high-quality randomized controlled trials (RCTs) are necessary to definitively establish caffeine's role in managing adult constipation.