Background: Stroke is the world's first cardiovascular disorders. The stroke patients are at risk of gastrointestinal problems such as constipation and flatulence that cause complications include increased intracranial pressure and reduce capacity respiratory in these patients. This study aimed to evaluate the effects of synbiotic supplementation on stroke patients admitted to ICU with constipation and flatulence.Methods: This study is a randomized two groups clinical trial on 65 stroke patients admitted to the ICU Taleghani hospital in Mashhad for simple random sampling available was performed. Patients were randomly divided into two groups: intervention group (n=33) and control group (n=32) and the number of bowel movements and abdominal circumference were measured before the study. Patients in the intervention group, in addition to usual care, for one week; every 12 hours; received synbiotic supplement and the control group only received conventional treatment. In the end; the frequency of bowel movements and abdominal circumference of all the patients; were again check. Data by using; Poisson regression data correlated model and analysis of covariance, using SAS version 9.1 and SPSS version 11.5; at 95% confidence level; was analyzed. Results were compared between the two groups. Results:In the Intervention group the average number of bowel movements 1.22 and in the control group was 0.62 (p<0.0001). Also measured waist size in both intervention and control groups showed that abdominal circumference on average in the intervention group than the control group decreased by 1.6 cm and this change was significant (p=0.028). Conclusion:This study showed that synbiotic supplementation consumption increased bowel movements and reduce abdominal circumference in patients with stroke. Therefore, probiotics can be used as a non-drug treatment in patients with constipation and abdominal bloating.