Background/Aims: Constipation is a common gastrointestinal disease that reduces the quality of life and incurs considerable medical expenses. Bisacodyl and sodium docusate are generally used to treat constipation. This study assessed the effectiveness and safety of Goodmorning S Granule® (Hanpoong Pharm. Co., Ltd., Wanju, Korea) in functional constipation by a comparison with bisacodyl. Methods: A 2-week randomized, double-blind, active-controlled exploratory clinical trial was conducted to compare the treatment (Goodmorning S Granule® ) with the control (bisacodyl). The efficacy was measured by the changes in transition, Bristol stool type, stomachache, clinical manifestation, defecation time after drug consumption, 36-item short-form survey (SF-36), and the results of improvement evaluation. The safety was evaluated by the incidence of adverse drug events and vital signs. Additional analyses were conducted by dividing the severity according to the proportion of Bristol Stool Scale types 1 and 2. Results: Subjects were randomized to the treatment (n=24) or control (n=26) groups. No significant differences were observed in demographics. After 2 weeks from the baseline, the changes in the complete spontaneous bowel movement (CSBM) were higher in the treatment (4.00±2.62) group than in the control group (1.40±2.34) (p<0.05). The treatment group exhibited significant improvement in the score on the SF-36 questionnaire. The clinical side effects, such as stomachache and borborygmus, were reduced in the moderate constipation patients in the treatment group, according to additional analyses. Conclusions Goodmorning S Granule® , a herbal medicine, was more effective in improving quality of life and CSBM per week and safer in the moderate constipation groups because of the reduced clinical side effects.