Comparative efficacy of dioctahedral smectite (Smecta) and a probiotic preparation in chronic functional diarrhoea

The present study was designed to investigate the clinical efficacy and safety of dioctahedral smectite in Chinese patients with chronic functional diarrhoea and to compare this activity to a probiotic preparation.

Patients diagnosed with chronic functional diarrhoea (Rome II criteria), exclusion of blood, ova/parasites in the stool and a normal colonoscopy were included. After a 1-week period of baseline without any medication, they were prescribed three sachets of dioctahedral smectite 3 g, administered 1 h after the meals (Group A), or two capsules of Bifico 210 mg (Group B) for 28 consecutive days. Efficacy of the treatments was assessed on frequency of bowel movements and consistency of stool, as compared to baseline.

Four hundred and ten patients were included (258 males, 152 females; mean age 43.8 ± 13.9 years): 208 in Group A and 202 in Group B. In Group A, the mean number of stool per day decreased from 3.5 ± 1.0 at baseline to 2.0 ± 0.9 and from 3.3 ± 1.0 to 2.2 ± 0.9 in Group B (z = 2.699; P = 0.007). Decrease in stool number was significant with both treatments but more important with smectite at week 2 and remained significant throughout the treatment period. Stool consistency, assessed by the Bristol scale, also improved significantly over the treatment period, as compared to baseline (z = 3.310, P = 0.001).

Dioctahedral smectite appeared in this study to be an effective and safe treatment of chronic functional diarrhoea, its effect starting during the first week of treatment and consisting in a decrease in the frequency of daily bowel movements and improvement of stool consistency. Moreover, dioctahedral smectite displays a prolonged action after disruption of the treatment that may interfere with the natural course of the disease.