The time of defecation after taking laxatives depends mainly on the type and dosage of the laxative, as well as the sensitivity of the body to the drug, and there is generally no fixed time. If you take laxatives for constipation, the drugs are mostly slow-acting drugs, and defecation usually starts in about 6-8 hours, but the exact time depends on the amount of medication taken. If you are taking laxatives for colonoscopy, lower gastrointestinal tract imaging or intestinal surgery, they are mostly fast-acting drugs, and you may have a bowel movement in 30-60 minutes. Constipation can take laxatives to assist defecation, but need to be applied briefly, laxatives only laxative effect, no therapeutic effect, long-term use can cause the intestinal wall nerve dysfunction, causing a decrease in intestinal tone but aggravate the symptoms of constipation, and easy to form a dependence, and even cause colonic melanosis, inducing cancer. Normally, it is recommended to develop good bowel habits, drink more water, eat more vegetables and fruits, and exercise more to promote gastrointestinal motility.