Vomiting is a reflex action of the stomach contents and part of the small intestine contents going up in the digestive tract and expelling from the mouth, which is a manifestation of digestive tract dysfunction. Vomiting is a common symptom in newborns. Our stomach is like a pocket, connected to the upper esophagus and the lower intestine. Vomiting is due to the reverse peristaltic movement of the esophagus, stomach and intestines in the opposite direction of the normal peristaltic movement, coupled with strong spasmodic contractions of the abdominal muscles, resulting in the gushing of food and gastric juices from the mouth and nose. The typical vomiting action has three steps: 1) peristalsis begins in the body of the stomach and is conducted downward to rest at the gastric angle notch, where a strong contraction is produced and the stomach contents cannot be pushed downward; 2) the epiglottis is closed and the soft palate is lifted, separating the pharynx from the trachea and the nasal passage; 3) the cardia is opened, the esophagus is relaxed, the diaphragm is fixed in a deep inspiratory position, and the abdominal muscles suddenly contract and the stomach contents are squeezed and expelled through the esophagus. Etiology There are many diseases that cause vomiting in newborns, such as improper feeding, irritation of the gastric mucosa, dysfunction of the gastrointestinal tract, infectious diseases inside and outside the intestinal tract, central nervous system diseases and genetic metabolic diseases, and developmental malformations of the gastrointestinal tract. Some diseases, such as gastric perforation, compression of the esophagus by vagal vessels, annular pancreas, gastrointestinal duplication, incarcerated hernia, intussusception, appendicitis, etc., can also cause vomiting . Pathogenesis The common causes and clinical manifestations of vomiting in neonates are different from those in other age groups, mainly related to the characteristics of neonates: 1. Neonates have a looser esophagus, small gastric volume, horizontal position, better development of the pyloric sphincter and poor development of the cardia sphincter, poorer neural regulation of intestinal motility, and higher abdominal pressure, all of which are anatomical and physiological reasons for the ease of vomiting in neonates; 2. Abnormalities in the differentiation and development of organs during the embryonic period, especially in the anterior, middle and posterior intestines, which can easily cause malformations of the digestive tract, so that ingested food or digestive secretions cannot pass smoothly through the intestine and are discharged retrogradely from the mouth, forming vomiting; 3. Stimulation at birth, such as swallowing a large amount of amniotic fluid, blood, and rapid changes in the internal and external environment after birth, can also easily induce vomiting in newborns; 4. The vomiting center is not well developed and is easily stimulated by toxins produced by systemic inflammation or metabolic disorders causing vomiting. The significance of vomiting is to vomit out harmful substances out of the body, under certain conditions have a protective effect on the organism but frequent, violent vomiting, can cause a large amount of digestive fluid loss. Newborns have poor regulation of water and electrolyte metabolism, which can easily cause dehydration, electrolyte disorders and acid-base imbalance. Prolonged vomiting can lead to malnutrition and impaired growth. Moreover, the new growth has poor throat reflex, and when vomiting occurs, it may even aspirate vomitus into the respiratory tract, causing aspiration pneumonia and asphyxia, which is harmful to newborns and should be taken seriously by clinicians. The clinical manifestations of internal vomiting 1, milk spill Most children in the neonatal period are more or less the same present milk spill, milk spill does not belong to the real vomiting. Breast milk overflow can appear soon after the birth, mainly after feeding, that is, 1-2 mouth milk flow back into the mouth or spit out, after feeding change position is also easy to cause overflow. If the milk stays in the stomach for a long time, it can contain milk clots. Breast milk overflow does not affect the growth and development of newborns and gradually decreases with age, disappearing around 6 months after birth. It is generally believed that the cause of overflow is due to the incomplete development of elastic and muscular tissues in the esophagus of newborns, and no special treatment is needed. 2, uncoordinated swallowing action Common in premature infants, or in children with cranial and cranial neuropathy, is due to neuromuscular dysfunction of the pharynx and uncoordinated swallowing action, manifested by frequent retention of secretions in the pharynx, swallowing part of the milk into the esophagus, part out of the nasal and oral cavity, and part into the respiratory tract, causing neonatal pneumonia. The prognosis for those with neurological damage depends on the recovery of the nervous system itself. 3, improper feeding about 1/4 of the newborn vomiting. feeding too often, feeding too much milk; nipple hole is too large or too small, nipple sunken, resulting in the inhalation of a large number of production air; nipple into the mouth too much, stimulating the pharynx; milk too hot or too cold, milk party changes and concentration is not appropriate; feeding sick after violent crying, milk too much too early to turn the child, etc., are likely to cause neonatal vomiting. Vomiting can be light and heavy, not every time after milk. The vomit is milk or milk lumps, without bile. The above situation mostly occurs in the first child, the mother lack of feeding experience caused by the improvement of feeding methods can prevent vomiting. Under normal circumstances, the gastrointestinal tract is fully formed at four months of gestational age, and the fetus swallows amniotic fluid into the gastrointestinal tract, which has no obvious stimulation of the fetal gastric mucosa. During labor, such as overdue delivery, obstructed labor, intrauterine distress or asphyxia, the fetus swallows too much amniotic fluid, contaminated amniotic fluid, secretions in the birth canal or blood, which can irritate the gastric mucosa and cause vomiting. Vomiting can be manifested as vomiting immediately after birth, aggravated by vomiting after breastfeeding, and non-jet vomiting. The vomit is foamy and mucus-like, or a coffee-colored liquid if it contains blood. Most of the vomiting disappears within 1-2 days after birth, after the swallowed amniotic fluid and the contents of the birth canal are vomited up. If there are no other complications, the general condition of the child is normal, not accompanied by cyanosis and choking cough, mild cases do not require special treatment, heavy cases can be cured with 1% sodium bicarbonate gastric lavage 1-2 times. 5, pyloric spasm for the temporary dysfunction of the pylorus caused. Most of the onset within a week after birth, intermittent jet vomiting, not every time after milk vomiting. The vomit is milk, may have milk lumps, does not contain bile. The effect on systemic nutrition is low. Gastric pattern and peristaltic fluid are less frequently seen on examination, and the enlarged pyloric sphincter is not palpable on palpation. Treatment with atropine is effective. 6, vomiting caused by drug effects, infection, neonatal hepatitis, neonatal constipation, elevated intracranial pressure, genetic metabolic diseases, allergic diseases, etc. The vomit is white gastric contents. Suspicion of these diseases should be promptly seen by a pediatrician in order to clarify the diagnosis and give early treatment. The clinical manifestations of surgical vomiting 1, gastroesophageal reflux Many newborns have reflux phenomenon, but there are obvious signs of about 1/300-1/1000, the cause may be related to esophageal neuromuscular insufficiency and cardia relaxation. more than 90% of the children can vomit within the first week after birth, often occurring when lying down, vomit for milk, does not contain bile, vomit can be mixed with blood. Long-term gastroesophageal reflux can cause reflux esophagitis and esophageal ulcers. The treatment is to thicken the milk to reduce its fluidity and prevent upward spillage. Most of the symptoms disappear on their own at 6 months, but if there are still symptoms consider surgery. The incidence of esophageal atresia and esophagotracheal fistula is 1/3000-1/4500, about 1/3 of premature babies. due to fetal esophageal atresia, they cannot swallow amniotic fluid, and mothers often have amniotic fluid over. After birth, there is a lot of choking, bruising and aspiration pneumonia, and even asphyxia. Most children present to the clinic with aspiration pneumonia, and even severe infection before obtaining treatment. Early diagnosis and timely treatment is the key to improve the survival rate of surgery. The incidence of diaphragmatic hernia is 3.1/1000 in China and 1/2200 in foreign countries, mostly on the left side, often associated with intestinal malrotation, congenital heart disease and pulmonary dysplasia. After birth, paroxysmal shortness of breath and cyanosis, violent vomiting, rapid deterioration of general condition in severe cases, and high mortality rate. On examination, the epigastric depression is boat-shaped and paradoxical breathing may be seen. x-ray examination confirms the diagnosis, with inflated intestinal curvature and gastric alveolar shadow seen in the chest, pulmonary atelectasis, mediastinal displacement to the opposite side, and reduced or absent inflated abdominal shadow. Diaphragmatic hernia is treated surgically in emergency cases and the mortality rate is now greatly reduced due to the establishment of neonatal care units. 4. esophageal hiatal hernia It is a congenital defect in the development of the diaphragm that allows part of the stomach to enter the thoracic cavity through the esophageal hiatus. 85% of the children develop vomiting within the first week after birth, and 10% develop within 6 weeks after birth. Vomiting is not present in the standing position, but is obvious in the recumbent position and can be jet vomiting. 1/3 of infants can develop aspiration pneumonia. Gastric ulcers and occasionally gastric necrosis can occur in paraesophageal hernia and require emergency surgical management. Vomiting may persist for 12-18 months and disappears in most children when the body is upright. Sliding hernia can disappear on its own during the growth and development of infants, and is usually treated by postural therapy. For those with severe anemia, growth disorders, large intrathoracic gastric vesicles, or paraesophageal hernia, early surgery is indicated. 5, congenital hypertrophic pyloric stenosis occupies the third place of congenital gastrointestinal malformations, with an incidence of 0.3/1,000-1/1,000. male infants have a high incidence, with a male to female ratio of 4:1, mostly seen in full-term infants, with a genetic tendency. Vomiting begins around the second week of life and is persistent and progressive, gradually developing into jet vomiting. The vomit is milk and milk lumps, in large amounts, with a sour odor and bile. Soon after or during each feeding, the child has a good appetite and a strong sense of hunger. After repeated vomiting, the child does not gain weight and has decreased urine and stool. On abdominal examination, a distinct gastric pattern and gastric peristaltic waves in both prograde and retrograde directions can be seen. A hard mass of olive size can be palpated on the lateral aspect of the rectus abdominis muscle under the right costal margin, which is a hypertrophic pyloric sphincter. In severe cases of vomiting, dehydration, hypoxemia, hypokalemia and disturbance of acid-base balance are seen. The diagnosis is made by a barium meal with an enlarged stomach, prolonged gastric emptying time, typical beak-like changes in the pylorus, and a narrow and prolonged pyloric duct. Ultrasonography has a tendency to replace barium meal examination, which allows direct visualization of the hypertrophied pyloric sphincter. The diagnosis is clear and can be treated surgically with good results. 6, pyloric antrum, gastric torsion: vomit is white gastric contents, without bile. Barium meal angiography for clear diagnosis 7, congenital intestinal atresia, congenital intestinal stenosis, meconium peritonitis is a common cause of intestinal obstruction in the neonatal period, the vomit contains bile, with the increase in the number of breastfeeding, the child vomiting gradually aggravated, is persistent repeated vomiting. There is little fecal discharge and no normal fecal discharge in intestinal atresia. Abdominal X-ray, barium meal angiography and barium enema can clarify the diagnosis. After the diagnosis is confirmed, actively improve the general condition of the child and operate urgently. 8, congenital intestinal malrotation is a relatively common GI malformation, accounting for the 4th place of GI malformations in China. The main manifestation is the high incomplete obstruction of the ecliptic, generally in the 3-5 days after birth began to vomit, vomiting can be intermittent, sometimes light and sometimes heavy, vomit for milk, containing bile. After birth, the fetal stool is expelled. If the twist is reset, the symptoms disappear. If gastrointestinal bleeding occurs, suggesting intestinal necrosis, followed by intestinal perforation and peritonitis, positive peritoneal irritation signs, toxic shock, etc., if not operated in time, death can occur in a short period of time. x-ray standing film can be seen in the dilated stomach and duodenum, with double bubble sign, jejunum and ileum with little or no gas, barium enema shows that most of the colon is located in the left abdomen, the cecum is located in the left upper abdomen or mid-abdomen to confirm the diagnosis. 9, neonatal necrotizing small bowel colitis It is currently believed that infection plays a major role in the pathogenesis of this disease. The main manifestations are abdominal distension, diarrhea, vomiting and blood in the stool, serious symptoms of infection and toxicity, often complicated by sepsis, shock, peritonitis, intestinal perforation, etc. X-ray plain film examination and ultrasonography are important diagnostic tools for this disease. Early diagnosis and timely treatment are the keys to reduce the mortality of the disease. 10, congenital megacolon congenital megacolon is a common gastrointestinal malformation, accounting for the second digestive tract malformation, the incidence of China is about 1/2000-1/5000, the ratio of men to women is 4:1, there is a tendency of family morbidity. Due to the incomplete development of the intermuscular plexus of the intestinal wall at the end of the colon and the absence of ganglion cells, the affected intestinal segment is often in a spastic state and narrowed, and feces accumulates in the proximal colon, and the intestinal wall above the narrowing expands and thickens, resulting in a giant colon. (1) short segment type, the lesion is limited to the lower rectum, accounting for 8%; (2) common segment type, the most common, the lesion reaches from the anus up to the distal sigmoid colon, accounting for 75%; (3) long segment type, the lesion extends above the descending colon, accounting for 20%; (4) total colon type, the lesion includes the entire colon and the end of the ileum, accounting for 2%; (5) total colon type, the lesion includes the entire colon and the end of the ileum (4) total colon type, the lesion includes all the colon and the end of the ileum, accounting for about 2%; (5) total intestine without ganglion cell disease, less common. Clinical symptoms: (1) Meconium constipation: no meconium is excreted 24-48 hours after birth (98% of normal newborns excrete meconium within 48 hours after birth), or only a small amount of meconium, which must be excreted by rectal examination or enema. (2) Vomiting: vomiting is infrequent and small, but it may be frequent. The vomit is white gastric juice at first, and then becomes yellow-green with bile-like liquid. (3) Abdominal distention: the abdomen is distended and frog-shaped. Some children have difficulty breathing due to extreme distension of the abdomen. (4) Rectal examination: abdominal distension improves after rectal examination or enema with large amount of fetal stool and gas. Complications: Most of them occur within 2 months. (1) Intestinal obstruction: on the basis of constipation and partial intestinal obstruction, gradually or suddenly become complete intestinal obstruction, and in severe cases, death. (2) Small bowel colitis: It is a serious complication of neonatal megacolon. The symptom is diarrhea, mostly with strange smelly stools. It is accompanied by high fever, vomiting, dehydration, and electrolyte disturbance. (3) Intestinal perforation: In small bowel colitis, it leads to increased pressure in the colon and mucosal ulceration, which can lead to intestinal necrosis and intestinal perforation if not treated in time, which is life-threatening. (4) Systemic complications: poor resistance, easy infection, and general edema. Treatment: (1) Non-surgical treatment: reflux enema, enhanced supportive therapy. (2) Colostomy: sigmoid colostomy is feasible in neonates with unsuccessful enema. (3) Radical megacolon surgery: the best age is currently considered to be around 3 months. The common type of radical surgery for megacolon is mostly performed through the anus. The surgery has little damage, quick recovery, no exposed incision and few complications. 11.Anal and rectal malformation mainly refers to congenital anal atresia, congenital anal stenosis and atresia or stenosis of the rectum, which is the most frequent gastrointestinal malformation in the neonatal period, about 0.75/1000. about 50% of anorectal atresia is combined with various fistulas, including recto-vesical fistula, recto-urethral fistula and recto-perineal fistula in male infants, and recto-vaginal fistula, recto-vestibular fistula and recto-perineal fistula in female infants. Children with anal and rectal malformations often have combined genitourinary tract malformations and malformations elsewhere in the gastrointestinal tract. The clinical presentation varies due to the variety of forms of malformation, combined fistulas or other malformations. In anorectal atresia, no feces is passed after birth, and symptoms of low-level intestinal obstruction, such as abdominal distention, vomiting, and vomit containing bile and fecal-like material, gradually appear. Most children can be found to have no anus or an abnormal anus by careful examination. After 24 hours of life, lateral radiography in the inverted position is performed to determine the type of anorectal malformation and to determine the surgical plan. The difficulty of surgery varies greatly depending on the type of anorectal malformation, and multiple surgeries are required for high-grade combined fistulae.