As people’s health awareness is continuously strengthened, gastroenteroscopy is gradually recommended as a checkup for gastrointestinal diseases and a routine physical examination program for middle-aged people and above. As colonoscopy is more complicated and difficult than gastroscopy, adequate, careful and correct preparation before the examination is particularly important, and the examinee must carefully understand and respect the doctor’s instructions and implement them conscientiously in order to make the preparation fully effective and to improve the efficiency and accuracy of colonoscopy. How should the examinee prepare for colonoscopy carefully and adequately? I will be from, dietary arrangements, laxatives to take, preoperative medication for three aspects of a detailed explanation, I hope to help all readers and their friends. First, the dietary arrangements before colonoscopy: First of all, no matter what kind of laxatives used before the examination to do the preparation of clean bowel, can not guarantee the absolute cleanliness of the intestinal tract, especially for those who have stubborn constipation, the use of laxatives usually can not achieve satisfactory results. Therefore, strict dietary restrictions before colonoscopy become very necessary and practical. Here, I must seriously advise you that from the day you know for sure that you are going to have a colonoscopy (usually 3 to 5 days), you must not eat fiber-rich foods that are difficult to excrete in the short term, such as tomato skins, mushrooms, especially mushrooms, seaweed, seaweed, seaweed, seaweed, seaweed, melons with seeds, etc. In many cases, these things are retained in the stool and are not excreted in a short period of time. In many cases, these items are retained in the large intestine, causing great trouble in examinations and treatments, and even necessitating the discontinuation of examinations and microscopic treatments. Routine dietary preparations from the colonoscopy three days before the examination must begin: the 3rd and 2nd day before the examination shall change the diet for less slag or half-slag semi-liquid diet, such as porridge noodles rice flour eggs, etc.; 1 day before the examination changed to fluids, such as milk broth broth, etc.; the examination of the first day of the evening at eight o’clock to start fasting; for the constipation of the examined person is best to start three days before the examination of fruit guide tablets and other diarrheal medicines. Second, colonoscopy examination before the laxative taking method: At present, the world’s most safe and effective drug intestinal cleansing method is: PEG liquid intestinal cleansing method (PEG a ELS): the Chinese name of this drug: compound polyethylene glycol electrolyte bulk, belongs to a new generation of oral total intestinal lavage solution. Its Chinese trade names are: Hengkang Zhengqing and Shuang or Fu Jingqing. For most people, a total of two boxes will be enough, each box contains a total of ABC three sachets, each box is formulated into 1000mL of liquid, two boxes of a total of 2000mL of liquid. But for people with chronic constipation, they may need 3 or 4 boxes to make 3000 or 4000mL of liquid. Specific methods: 1, the day before the colonoscopy lunch and dinner must enter the liquid diet 2, the day of the examination at 6:00 in the morning to take PEG a ELS liquid 2000mL can be. If the night before at seven o’clock to take laxative fruit guide tablets 6 tablets better. 3.Please note: Do not drink 1000 or even 2000mL at one time, as this will cause severe gastrointestinal discomfort and be very unpleasant. It should be the first time to take 500mL, and then take 250mL every 20 minutes, two hours to finish, so that the gastrointestinal tract has a gradual adaptation process, which will make us much more comfortable. If you feel that it tastes bad, you can add a small amount of sugar or fruit juice to adjust the flavor appropriately and improve the taste. In addition, some hospitals will add a foam remover: dimethylsiloxane dispersant and a mucus remover: streptomycin to improve the clarity and effect during colonoscopy. 4. Until the excrement becomes clear water-like to ensure that the effect of intestinal cleansing is achieved, if there is still fecal sludge in the excrement, you can continue to drink water, or even increase the medication appropriately. At the same time, after taking the medicine, it is necessary to leave enough time for defecation before colonoscopy, otherwise there will be a large amount of fecal water and air bubbles retained in the intestinal lumen during the examination, which will seriously affect the observation of colonoscopy and microscopic treatment. Other intestinal preparation drugs used in the past are magnesium sulfate mannitol, etc., but there are certain drawbacks and dangers, so the clinic has been used sparingly, and we will not do a detailed introduction here, and if you need to use it, please follow the doctor’s instructions strictly. Third, colonoscopy before the auxiliary drugs: There are two main drugs: 1, antispasmodic ② sedative, are injected intravenously 5 minutes before the examination. 2, antispasmodic drugs: generally with scopolamine (654 a 2), antispasmodic, or Nosopa injection. The main role is to eliminate the spasm of the intestinal tube, so that the intestinal tube is in a state of relaxation, to facilitate colonoscopy. 3, sedative drugs: the general use of Butofenol midazolam or imidazolam, mainly used for preoperative excessive tension or special fear of pain, in order to ensure that the examination is carried out smoothly. Its disadvantages are: make the examined person’s responsiveness decreased, pain insensitivity, easy to occur during the examination of intestinal perforation complications. It should be used with caution, especially for those who have undergone abdominal surgery and have intestinal adhesions.