Drinking saline water how long to have a sense of defecation can not be determined, because drinking saline water to promote the role of defecation is not obvious. Saline is a relatively low concentration of salt water, saline has a certain role in promoting intestinal peristalsis, but the effect is slight, if the defecation is more difficult to drink saline is not a great role, drink after the general can not promote defecation. And generally do not recommend drinking too much salt water, after entering the intestine will be quickly absorbed by the intestine. If there is difficulty in defecation, it is necessary to adjust the diet appropriately, eat more vegetables and fruits, increase the intake of dietary fiber, and drink more water. However, if severe constipation occurs, you need to cooperate with your doctor to take laxative drugs, such as lactulose. It is recommended that if there is difficulty in defecation, go to the hospital in time to identify the cause and cooperate with the doctor to deal with or treat. Medications need to be used under the guidance of a doctor.