How long does it take to go to the bathroom after drinking senna cannot be generalized, its specific onset of action time is related to the dosage, physical condition, type of disease and many other factors. Senna is the dried leaflet of the cassia plant, whose main component is an anthraquinone derivative, this substance can stimulate the intestinal mucosa and nerve tissue, enhance its peristaltic and contractile function, accelerate the metabolic substances in the body to advance, so as to achieve the effect of heat, diuretic, laxative. In general, most patients with constipation can see the effect within half an hour to a few hours after taking senna water in sufficient quantity under the guidance of a doctor. However, in some cases, due to the severity of constipation, or insensitivity to senna, or insufficient dosage, the specific effect time may be slightly delayed, or even can not see obvious results. It should be noted that because of the strong effect of senna, the daily consumption process, the frequency of consumption and dosage should be controlled to avoid long-term or excessive consumption, to prevent diarrhea, abdominal pain, black stool and other adverse symptoms reactions.