Syzygium cumini L. Skeels (Myrtaceae) commonly known as jambolan is used as traditional medicine to treat gastrointestinal disorders in children in Brazil. This work is one of the first to evaluate the antidiarrhoeal and antispasmodic activity of the standardized extract of S. cumini leaves (HESc) in experimental models in vitro and in vivo rodents. Mice pre-treated with HESc (100, 250 and 1000 mg/kg) and atropine (1.0 mg/kg) had reduced intestinal transit velocity of 11.0; 23.2 and19.1%, respectively compared to saline control (46.6±0.9). In isolated rats jejunum, HESc (50, 150 and 300 µg/mL) shifted to the right cumulative concentration-response curves to ACh with changing maximum effect (E max ), which is characteristic of non-competitive antagonism to ACh. HESc also promoted relaxation (E max 90.2±5.8%) in preparations pre-contacted with KCl (75 mM). Additionally, it reduced the maximal CaCl 2 -induced response in 15.4; 56.3 and 92.1% in a concentration-dependent manner. The study results show that HESc has an antidiarrhoeal and spasmolytic potential that can be partly explained by the reduction of intestinal transit velocity and blockage of the voltage-dependent calcium channels in the smooth intestinal muscle.