Let's talk about gastrointestinal endoscopy

Author: Wei Jian, deputy chief nurse, Beijing Friendship Hospital, Capital Medical University

Reviewer: Yao Shukun, Chief Physician, China-Japan Friendship Hospital

In my country, the incidence and mortality rates of esophageal cancer, gastric cancer, and colorectal cancer among digestive tract tumors are both high, which seriously threatens the life safety and health of the public. The most important thing for cancer prevention and control is early diagnosis and early treatment. Digestive endoscopy is used for the diagnosis and treatment of digestive system diseases [1], which is an important means to achieve early diagnosis and screening of digestive tract tumors.

The most common digestive endoscopy is gastroscopy and colonoscopy. Both gastroscopy and colonoscopy are invasive procedures. During the examination, the doctor needs to insert a gastroscope or colonoscope into the body and use the endoscope to observe the digestive tract mucosa to detect lesions or abnormalities, so as to achieve the purpose of screening and diagnosis.

Digestive endoscopy will cause us physical discomfort during the entire examination process. For example, when the gastroscope passes through the pharynx, there will be obvious nausea, salivation, and dry heaving; the colonoscope will cause abdominal distension and pain when passing through various sections of the intestine.

Therefore, when it comes to gastroscopy and colonoscopy, it is inevitable that people will feel anxious and fearful. However, with the advancement of technology, painless gastroscopy has been widely used, which solves the discomfort during the examination. The examinee can complete the examination in a good "sleep", which greatly improves the comfort of gastroscopy.

Since gastroscopy and colonoscopy are not easy to perform, everyone must want to get high-quality examination results every time. A major factor determining high-quality results is to strictly follow the medical guidance before the operation to make preoperative preparations.

Let’s talk about some things about gastrointestinal endoscopy in detail, which will help you have a deeper understanding so that you can make accurate and standardized preoperative preparations for gastroscopy and colonoscopy, and complete the endoscopic examination smoothly and with high quality.

1. Do I need to fast before gastroscopy?

Gastroscopy requires fasting for two purposes.

Figure 1 Original copyright image, no permission to reprint

First, when the gastroscope enters the upper digestive tract, changes in the esophagus and gastric mucosa need to be observed. If there is food, the mucosa will be covered and the purpose of the examination cannot be achieved. Second, if there is food in the stomach, nausea and vomiting will occur during the insertion of the scope, and the food will reflux and easily enter the trachea, causing accidents such as choking, aspiration, and suffocation, which is very dangerous.

Therefore, you are required to fast before gastroscopy. Generally, you should fast for at least 6 hours and 2 hours before the examination. However, if you have weakened gastric motility, gastric retention, achalasia, etc., you should follow the doctor's advice to appropriately extend the fasting and abstinence time.

Figure 2 Original copyright image, no permission to reprint

2. Do I need to fast before a colonoscopy? What dietary preparations do I need to take?

The dietary preparation before a colonoscopy is more complicated than that before a gastroscopy. This is because a colonoscopy uses the camera in front of the endoscope to observe the intestinal cavity. Therefore, food residues (feces) in the intestine must be cleaned before the examination. This is very important. Imagine how to observe the intestinal mucosa if there is feces or even stool in the intestinal cavity.

Figure 3 Original copyright image, no permission to reprint

Therefore, dietary restrictions are required the day before the colonoscopy, and you also need to fast on the day of the examination. Especially when choosing a painless colonoscopy, you must strictly follow the requirements of fasting for at least 6 hours and not drinking for 2 hours to avoid the risk of anesthesia.

Review your meal preparations from the previous day

The day before the colonoscopy, you are required to eat a low-fiber diet, or a semi-liquid or clear liquid diet [2]. The principle is to limit the amount of food you eat and the food you eat to avoid producing more food residues. However, you should not starve yourself too much to prevent hypoglycemia, fatigue, etc. The amount of food you eat can be reduced to 60%-70% of your usual amount, and you should eat small meals frequently. However, you must not eat what you are not allowed to eat.

Figure 4 Original copyright image, no permission to reprint

A low-fiber diet mainly includes refined rice and flour foods, such as steamed bread, white bread slices, boiled eggs, egg custard, tofu, milk, yogurt, white rice porridge, etc. Pay attention to eating small meals, soft and mushy, stewing more and less seasoning, fine processing of refined rice and flour, peeling, removing seeds and grains; do not eat vegetables with high dietary fiber, such as leeks, celery, kelp, etc.; do not eat all mushrooms, such as fungus, enoki mushrooms, mushrooms, etc.; do not eat all fruits, coarse grains, whole beans, nuts, etc. In this way, we can cooperate with the intestinal cleansing agent to prepare our intestines more cleanly and cooperate with the doctor to complete a high-quality colonoscopy.

3. Can I still take the long-term medications normally before undergoing gastroscopy and/or colonoscopy?

Before undergoing gastroscopy and/or colonoscopy, it is necessary to stop taking some drugs that may affect coagulation function, including some anticoagulants, antidepressants, etc. 7-10 days in advance. If some suspicious lesions are found during the examination, a pathological biopsy is generally required. If the above-mentioned drugs are not stopped, intraoperative bleeding may be caused.

It should be noted that whether or not to stop taking anticoagulants and how long to stop them should also be based on the opinions of relevant specialists. For example, patients who have undergone heart stenting should follow the advice of cardiovascular doctors. If the drug cannot be stopped, other drug alternatives can be used according to the doctor's advice, or gastroscopy or colonoscopy can be performed by observation only without pathological biopsy to avoid bleeding.

If you suffer from high blood pressure or diabetes, you need to take antihypertensive drugs normally, but be careful to control the amount of water you take with the medicine. Just take the medicine with a small sip of water on an empty stomach in the morning; but you must stop taking oral hypoglycemic drugs or injected insulin to avoid hypoglycemia.

4. How should I take bowel cleansing medicine before colonoscopy?

Colonoscopy requires good intestinal preparation as the basis, so the bowel cleansing effect after taking bowel cleansing medicine is very important. Generally speaking, the doctor will help you choose which bowel cleansing medicine to use and the dosage of the bowel cleansing medicine according to each person's individual situation, as well as whether other medications need to be used in combination.

The most commonly used bowel cleansing drug at present is polyethylene glycol electrolyte powder. This drug is relatively safe, will not affect the osmotic pressure, and will not cause dehydration, but there are still some key points to pay attention to when taking it.

Adults undergoing colonoscopy are generally given 3-4 bags of polyethylene glycol electrolyte powder, which is better when taken in divided doses. When taking the bowel cleansing medicine, pay attention to the water temperature, which should not be too hot, and use warm water to dissolve it. One bag of bowel cleansing medicine is mixed with 1000 ml of warm water. Take one bag of 1000 ml at 19:00 the night before the examination, and drink it within 1 hour. During the process of taking the medicine, you must walk more to facilitate excretion and relieve abdominal distension and abdominal pain. After taking the medicine, you can rest after the bowel movements gradually stop. The number of bowel movements varies from person to person.

If you are going to have a colonoscopy in the afternoon of the next day, you need to drink two more bags of bowel cleansing medicine at 7 a.m.; if you are going to have a colonoscopy in the morning of the next day, you need to get up early and start taking bowel cleansing medicine at 4 a.m. Of course, this time is not completely fixed. It should be calculated according to the specific scheduled colonoscopy time. It is best to take it 4-6 hours before the examination.

On the day of the examination, 2 bags of bowel cleansing medicine were dissolved in warm water, totaling 2000 ml. The first 1000 ml was required to be taken within 1 hour, and the second 1000 ml was taken in four times, that is, 250 ml every 15 minutes. Be sure to walk while taking the medicine to promote rapid excretion of the medicine, until the stool is light yellow or watery, without fecal residue, and transparent, which means that the bowel preparation is qualified.

Precautions when taking bowel cleansing medicine:

① Because patients will go to the toilet frequently during the process of taking bowel cleansing drugs and there are dietary restrictions in the early stage, they should pay attention to choosing a toilet and stand up and sit down slowly when going to the toilet, especially for some relatively older patients, to prevent the risk of falling.

② If you feel unbearable abdominal distension during taking the medicine, you can stop taking it, walk more, and continue taking it when you can tolerate it.

③If you feel that the bowel cleansing medicine tastes bad and makes you feel nauseous and want to vomit, you can add some of your favorite fruit juice drinks to relieve the discomfort so that you can complete the bowel cleansing medicine smoothly.

5. How to cooperate with the doctor to reduce discomfort during routine gastroscopy or colonoscopy?

When doing gastroscopy, as the endoscope passes through the pharynx and esophagus into the gastric cavity, you will experience nausea, vomiting, salivation, accelerated heartbeat, etc. At this time, please swallow, take a deep breath, inhale through your nose, exhale through your mouth, let saliva flow out naturally, do not hold your breath, and do not swallow your saliva. If you really cannot tolerate it, raise your hand to signal the doctor. The symptoms will improve after the gastroscopy passes through the pharynx. As long as you cooperate closely with the doctor, the examination can be completed smoothly. Don't worry too much.

During a colonoscopy, the doctor will inject air into the intestinal tract to prop it up for observation, which will cause abdominal distension and pain. You can gently rotate your abdomen clockwise to help expel gas. The doctor will also suck out the gas while observing to reduce discomfort. If the abdominal pain and distension are unbearable, please signal or inform the doctor in time.

6. What should I pay attention to after gastroscopy and/or colonoscopy? When can I eat?

There may be some discomfort after a gastroscopy and/or colonoscopy.

After gastroscopy, you may experience symptoms such as throat discomfort and abdominal distension, which will gradually ease. If the symptoms persist or worsen, please seek medical attention immediately.

The main discomforts after colonoscopy are abdominal distension and pain. You can take a proper walk and pass gas to help expel gas, so that the symptoms of abdominal distension and pain can be gradually relieved. If the symptoms persist or worsen, please seek medical attention immediately.

If you choose painless gastroscopy and/or colonoscopy, in addition to the above precautions, you must also pay attention to preventing falls. You must be accompanied by family members when leaving the hospital. You are prohibited from driving a motor vehicle, working at heights[3], signing important documents, doing detailed calculations, or engaging in extreme sports on the same day. Breastfeeding mothers should wait 24 hours before breastfeeding.

If no pathological biopsy is taken during the operation, you can eat after the general gastroscopy and (or) colonoscopy. You can drink a small amount of water before eating after the gastroscopy and observe whether you have symptoms such as choking, nausea and vomiting. If you do not have the above symptoms, you can eat normally, but you should pay attention to choosing easily digestible food and avoid food that causes abdominal distension and spicy stimulation.

If a pathological biopsy was taken during the operation, you can eat 2 hours after the examination, and make sure to eat some warm or cold semi-liquid food within 24 hours, in small amounts and frequent meals, to facilitate the healing of the wound at the biopsy site. Then you can slowly resume a normal diet.

Figure 5 Original copyright image, no permission to reprint

The above is some knowledge you need to know about gastroscopy and (or) colonoscopy. Have you remembered it? Gastroscopy and colonoscopy are powerful tools for early screening of digestive tract cancer. I hope that with the above knowledge, you can prepare well before the examination and complete high-quality gastroscopy and colonoscopy.

References

Allemani C, Matsuda T, Di Carlo V, et al. Global surveillance of trends in cancer survival 2000-14 (CON-CORD-3): analysis of individual records for 37513025 patients diagnosed with one of 18 cancers from 322

population-based registries in 71 countries [JJ. Lancet,2018,391(10125):1023-1075.

[2] Digestive Endoscopy Committee of the Endoscopy Branch of the Chinese Medical Doctor Association, and Oncology Endoscopy Committee of the Chinese Anti-Cancer Association. Chinese Guidelines for Bowel Preparation Related to Digestive Endoscopy Diagnosis and Treatment (2019, Shanghai) [J]. Chinese Medical Journal, 2019, 99(26): 2024-2035.

[3] Chinese Society of Digestive Endoscopy, Chinese Society of Anesthesiology. Expert consensus on sedation/anesthesia for digestive endoscopy in China. Chinese Journal of Digestive Endoscopy, 2014, 31(8):424.