Objective: Papaya (Carica papaya L.) is used as a natural remedy in abnormal digestion in tropical and industrialized countries. Besides this wide distribution little evidence has been produced with reference to its physiological effect in humans and the proof of efficacy. Former clinical observations had revealed positive effects for patients with constipation, heartburn, and symptoms of irritable bowel syndrome (IBS) after eating papaya preparations. In line with these former positive clinical observations, we studied the clinical effects of the papaya preparation Caricol® in a double blind placebo controlled study design.

Methods: In this study the participants were volunteers, with chronic (prevailing) indigestions and dysfunctions in the gastrointestinal tract. During the trial the intake of the substance of intent and placebo was 20 ml daily for 40 days. The endpoints were the frequency of 22 symptoms recorded before and after the documented intake recorded by questionnaire.

Results: The symptoms "Constipation", "Bloating", and "Heartburn" were defined as primary and frequency of "painful (straining) bowel movements" as secondary endpoint. The participation ended after the intake period within two days ("early returnees"). Wash out effects were observed in "late returnees", who returned with a delay of 8.6 (±5.95 days). In the verum group early returnees revealed statistically significant improvements of the symptoms "constipation" and "bloating". The analysis of "heartburn" felt short of significant improvement because of the small number of included cases with this criteria (N=13, p=0.114). None of the significant benefits were observed after the washout phase.

Conclusion: We conclude from these results, that the papaya preparation (Caricol®) contributes to the maintenance of digestive tract physiology. It ameliorates various functional disturbances, like symptoms of IBS. The mechanism of this digestive tract physiology support is discussed.