What is the aim of this review?
The aim of this Cochrane Review was to find out if smectite (or diosmectite), a medicinal clay commonly prescribed to people who have diarrhoea in order to reduce their stool output, helps children with acute diarrhoea. We collected and analysed all relevant studies to answer this question and found 18 relevant studies.
Key messages
Giving smectite to children with acute diarrhoea may reduce its duration. However, more high-quality studies are still needed, including studies that assess different causes of diarrhoea and the economic effects of this treatment.
What was studied in the review?
Acute diarrhoea is one of the most common diseases in children. It is usually caused by a viral infection. The main aim of treatment is to maintain a good level of hydration. This is achieved with oral rehydration solutions, and few children need to be hospitalized or require intravenous rehydration. Still, even with proper hydration, having loose stools is a burden for both parents and patients.
Smectite may help by reducing inflammation in the gut; by acting as a barrier to reduce the penetration of toxins; or by increasing water absorption.
What are the main results?
We found 18 relevant studies with 2616 children that were conducted in both high-income and low- or middle-income countries. These studies compared children receiving smectite with children receiving routine care or a placebo (a pill or liquid that contains no medicine). Eight studies were funded by the manufacturer.
Smectite may reduce the duration of diarrhoea by one day (low-certainty evidence); may increase the number of children cured by day 3 (low-certainty evidence); and may slightly reduce the quantity of loose stools (low-certainty evidence).
We are uncertain whether smectite has an effect on how many stools children have (very low-certainty evidence). It may not have an effect on how many children need to be hospitalized (low-certainty evidence), and probably does not have an effect on how many children need intravenous rehydration (moderate-certainty evidence).
We found no reports of serious adverse effects. Minor adverse effects included constipation, vomiting, and bad taste, but these did not differ between groups.
How up-to-date is this review?
We searched for studies published up to 27 June 2017.
Based on low-certainty evidence, smectite used as an adjuvant to rehydration therapy may reduce the duration of diarrhoea in children with acute infectious diarrhoea by a day; may increase cure rate by day 3; and may reduce stool output, but has no effect on hospitalization rates or need for intravenous therapy.
As mortality secondary to acute infectious diarrhoea has decreased worldwide, the focus shifts to adjuvant therapies to lessen the burden of disease. Smectite, a medicinal clay, could offer a complementary intervention to reduce the duration of diarrhoea.
To assess the effects of smectite for treating acute infectious diarrhoea in children.
We searched the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Pubmed), Embase (Ovid), LILACS, reference lists from studies and previous reviews, and conference abstracts, up to 27 June 2017.
Randomized and quasi-randomized trials comparing smectite to a control group in children aged one month to 18 years old with acute infectious diarrhoea.
Two review authors independently screened abstracts and the full texts for inclusion, extracted data, and assessed risk of bias. Our primary outcomes were duration of diarrhoea and clinical resolution at day 3. We summarized continuous outcomes using mean differences (MD) and dichotomous outcomes using risk ratios (RR), with 95% confidence intervals (CI). Where appropriate, we pooled data in meta-analyses and assessed heterogeneity. We explored publication bias using a funnel plot.
Eighteen trials with 2616 children met our inclusion criteria. Studies were conducted in both ambulatory and in-hospital settings, and in both high-income and low- or middle-income countries. Most studies included children with rotavirus infections, and half included breastfed children.
Smectite may reduce the duration of diarrhoea by approximately a day (MD -24.38 hours, 95% CI -30.91 to -17.85; 14 studies; 2209 children; low-certainty evidence); may increase clinical resolution at day 3 (risk ratio (RR) 2.10, 95% CI 1.30 to 3.39; 5 trials; 312 children; low-certainty evidence); and may reduce stool output (MD -11.37, 95% CI -21.94 to -0.79; 3 studies; 634 children; low-certainty evidence).
We are uncertain whether smectite reduces stool frequency, measured as depositions per day (MD -1.33, 95% CI -2.28 to -0.38; 3 studies; 954 children; very low-certainty evidence). There was no evidence of an effect on need for hospitalization (RR 0.93, 95% CI 0.75 to 1.15; 2 studies; 885 children; low-certainty evidence) and need for intravenous rehydration (RR 0.77, 95% CI 0.54 to 1.11; 1 study; 81 children; moderate-certainty evidence). The most frequently reported side effect was constipation, which did not differ between groups (RR 4.71, 95% CI 0.56 to 39.19; 2 studies; 128 children; low-certainty evidence). No deaths or serious adverse effects were reported.