This is a prospective, randomised, double blind, placebo controlled, parallel arm, cross-over, multicentre study conducted in a population of children and adults with abdominal symptoms observed at outpatient primary health care centres.

Inclusion criteria

1. Children and adults age >3 up to ≤ 75 years old. Boys and girls aged 3-15 years
2. Presence of abdominal symptoms
3. Informed consent for participation in the study signed by children' parents/ legal caregivers and child above 13 years old, all adults patients.

Exclusion Criteria:

1. Chronic intestinal disease, immunodeficiency or immunosuppressive treatment.
2. Chronic or acute diarrheal disease.
3. Use of laxatives or antydiarrhoeal treatment within the week before inclusion in the study.
4. Antibiotic treatment for the last four weeks before inclusion in the study.
5. Intake of probiotic products for the last two weeks before inclusion in the study
6. Known hypersensitivity to any of the ingredients in the probiotic product or the placebo (corn starch, magnesium stearate ± bacterial culture).