Prevalence of functional constipation (FC) was first determined with 15.2% reported. Next, a 16-week randomised, double-blind, placebo-controlled study conducted to assess the improvement in functional constipation among the respective individuals by using synbiotic supplement. Throughout the intervention, it was reported that significant improvements for defecation frequency, Bristol Stool Form (BSF) scale, and Patients Assessment of Constipation Symptoms (PAC-SYM) scores were reported within synbiotic group (p < 0.001). However, no significant different was reported when compared both groups as placebo group was found to have significant within-group difference too. Placebo effect was suspected in this study.

Digestive system disease is the top ten principal causes of morbidity and mortality among Malaysians whereby functional constipation (FC) is the commonest functional gastrointestinal disorders (FGIDs) reported. Although numerous treatments are available, but over-the-counter drugs which have low product safety and possible toxicity were always given as the treatment option. Synbiotic have been well-studied to improve digestive health includes constipation. Thus, the objectives of this study were to determine the prevalence of FC and to evaluate the effects of synbiotic supplement on improving FC symptoms and contributing factors among constipated individuals in Serdang, Selangor. This study comprised of two parts which were screening and intervention part. The prevalence of functional constipation was relatively high in the study community. Synbiotic supplement was effective in the improvement of functional constipation symptoms, quality of life, and psychological factors. However, the positive improvement in placebo group indicated the existence of placebo effects which led to the improvement in quality of life and changes in psychological factors. Therefore, the current findings are useful information for future intervention in improving functional constipation symptoms.

Inclusion Criteria:

• Malaysian of either gender;
• 18 to 65 years old;
• Body mass index (BMI) 16.0 to 29.9 kg/m2;
• Positively diagnosed with functional constipation with Rome III-defined constipation module by the gastroenterologist

Exclusion Criteria:

• Vulnerable groups of pregnant and breastfeeding women;
• Physically or mentally handicapped individuals;
• Diagnosed with organic constipation (constipation associated with any neoplastic diseases, neuropathy or mechanical obstruction);
• Diagnosed with cardiovascular diseases, diabetes mellitus, cancer, neurological disease or other serious illnesses or severe medical complications;
• Faced alarm features indicative of colorectal cancer, metabolic disease and a history of gastrointestinal surgery.

To avoid the likelihood of co-intervention bias, the following respondents were excluded:

• On gastrointestinal medications;
• Consumed probiotics or synbiotic products more than once a week in two weeks preceding screening or during intervention period;
• Regularly used laxatives (more than once per week), used anticholinergics, anti-diarrheals, antibiotics or laxative in two weeks preceding screening or at any point during intervention.