Rectal drug delivery Rectal drug delivery refers to the delivery of drugs into the intestinal canal through the anus, so that the drugs can be absorbed into the blood through the rectal mucosa to play the role of local treatment or systemic treatment. Modern medicine has confirmed that there are abundant arteries, veins and lymphatic plexuses around the rectum, and the rectal mucosa has a strong absorption function. Rectal drug delivery, the drug mixed in the rectal secretion, through the intestinal mucosa is absorbed, the treatment of chronic pelvic inflammatory disease, rectal drug delivery is the first in China, as far as the Han Dynasty there are records of rectal drug delivery, and now has been widely used in clinical. The rectum of adults is 15-20cm long and is very rich in blood circulation. Although the rectum does not actively absorb drugs like the small intestine, it can absorb drugs through passive diffusion. The scope of application of rectal drug delivery: chronic pelvic inflammatory diseases such as hydrosalpinx, pelvic effusion and pelvic inflammatory mass; benign internal genital tumors such as uterine fibroids and ovarian cysts without surgical indications; prevention of re-adhesion after hysterosalpingography and gynecological laparoscopy; endometriosis, pelvic stasis, chronic pelvic pain, etc. Features of rectal drug delivery: easy to release, easy to absorb and easy to spread. Advantages of rectal drug delivery: 1.Entering the body circulation through the inferior vena cava, acting on the whole body, not restricted by the physiological structure and female physiological cycle. 2.It does not pass through the upper gastrointestinal tract, which can avoid the influence of gastric acid and enzymes on the drug, and also avoid the stimulation of the stomach and intestines. 3.50% of the drug avoids the liver, the first-pass effect, reducing the side effects on the liver. 4, the drug through the rectal mucosa, intestinal wall, fluids and pelvic communication lymphatics, capillaries directly seized for the pelvic cavity, so that the disease drug concentration is high, the effect is strong. The transrectal inflammatory drug than oral drug bioavailability, the same dose of drugs rectal administration is greater than the role of oral drugs. According to the study, the Chinese medicine retains the enema in the speed of absorption, the speed of manifestation than pills, tablets, suppositories, tonics are faster, reach the peak concentration is high, reach the peak time is short.