Constipation is a gastrointestinal motility disorder, a common problem in both adults and children. Its 
worldwide prevalence ranges from 2.5% to 7.9% of the adult population and 0.7% to 29.6% in children [Mugie, 
2011]. Using a laxative is the most common way to relieve constipation. Laxatives can act by increasing intestinal 
motility and /or intestinal secretions [Brunton, 2012].Euphorbia heterophylla Linn. (EH) is a plant belongs to family 
Euphorbiaceae. It is formally known as “Yha-Yang” in Thailand and widely used for relieving constipation in the 
south of Thailand. It is distributed worldwide and has been used as a folk medicine. Its leaves are commonly used 
for its activity as an antioxidant, an anti-inflammatory and a laxative agent [Abbasi et al., 2013; Falodun et al., 
2006; Falodun & Agbakmuru, 2004]. The phytochemicals responsible for the laxative activity of E. heterophylla 
leaves have been shown to be carbohydrates and phorbol ester [Falodun & Agbakmuru, 2004]. However, its 
mechanism as a laxative is not known. The aims of this study therefore were to screen extracts from E. 
heterophylla leaves for their ability to induce motility in rat ileum and to determine its mechanism of action as an 
anti–constipation agent.