Ethyl p-coumarate (EC), a compound with a relatively strong activity was extracted from Rubus corchorifolius leaves by bioactivity-guided isolation. Dose responses of Rubus corchorifolius leaf extract (RE) and EC for inhibition of intestinal movement were studied in terms of movement of isolated rabbit intestine model. The effects of RE and EC as well as four spasmogenic agents (acetylcholine, phentolamine, histamine, and barium chloride) that are related to four key channels in antidiarrheal effects on the movement of isolated intestine were also investigated. The results showed that the tensional variation percentage (TVP) of intestine was above 30% when RE concentration was in the range of 1 to 10 mg/mL and reached maximum (45.37%) at 4 mg/mL. When the concentration of EC was in the range of 10 to 800 μg/mL, the inhibitory effect on intestinal movement was significantly higher than that of atropine (p < 0.01) at the same concentration and TVP value reached the maximum (70.45%) when the concentration of EC was 400 μg/mL. Thus, the inhibition of intestinal movement by RE was mainly achieved through its effects on the cholinergic M receptor of acetylcholine and histamine channels, whereas that by EC was mainly achieved through its effects on the adrenergic a-receptor, histamine channel, and calcium ion channel. Therefore, RE and EC act on different targets and are effective antidiarrheal drugs, where EC in RE exerts a significantly stronger effect than atropine.