Most babies vomit at one time or another, and some babies vomit a great deal. While most causes of vomiting in infants is self-limiting and benign, vomiting can also indicate a serious medical problem. The type, frequency and amount of vomiting, as well as the appearance of the vomit, all need medical assessment to help determine the cause of vomiting.
Gastrointestinal Reflux
Gastrointestinal reflux, also called GER or just reflux, occurs in all babies to some degree, with around 50 percent of babies younger than 3 months having at least one spitting-up episode a day, explains Harland Winter, M.D., of Harvard Medical School on Up To Date. Reflux, one of the most common causes of vomiting in infants, according to Joan Di Palma, M.D., of Thomas Jefferson University, requires medical attention in 20 percent of cases. Reflux occurs because the ring of muscle between the stomach and lower esophagus doesn't close completely in infants, so food spills back into the lower part of the esophagus and sometimes into the mouth. More than half of infants who spit up or vomit regularly stop by 10 months, when the angle of the stomach and esophagus changes. Overfeeding and air swallowing often cause reflux in infants. If gastrointestinal disease or GERD develops, the situation becomes more serious. Babies with GERD may fail to gain weight, refuse to eat, cry and arch their backs, and vomit more forcefully. Medications, formula changes and keeping a baby upright after feeding all may help decrease vomiting from GER or GERD.
Pyloric Stenosis
Pyloric stenosis, normally occurs in babies a few weeks old, with baby boys more likely to develop the condition than girls. The muscular valve at the end of the stomach that attaches to the small intestine grows more than usual, so that food has a hard time passing from the stomach. As this change is progressive, the infant may start with spitting up and progress to forceful, projectile vomiting of every feeding. The baby may become dehydrated, lethargic and pass little gas, and the valve itself may be palpated in some babies, feeling like a small hard, round olive. Pyloric stenosis requires surgical repair. Complications include bleeding, infection or intestinal leakage, according to the Mayo Clinic.
Allergic Gastroenteritis
Allergies to cow's milk and soy protein may cause chronic vomiting and failure to thrive, especially in babies who have a family history of food allergies, asthma or eczema, Dr. Di Palma says. Changing the diet usually helps, although medications may also have benefit.
Obstruction
Obstruction or blockage in the intestine causes green or bile-stained vomit that requires immediate investigation. Volvulus, or malrotation of the intestines that causes them to twist and block stool passage, is a rare condition that develops in less than 1 percent of infants, according to Dr. Di Palma. Volvulus usually occurs in infants with anomalies of the intestine, develops rapidly and is accompanied by green vomit, abdominal pain and distention and lethargy. Volvulus requires immediate surgery to save the bowel and in some cases, to save the infant's life. Other types of complete or partial bowel obstruction may also cause repeated vomiting of bile-stained fluid. Intestinal atresia, complete blockage, or stenosis, partial blockage, can develop in any part of the intestine but most often affect the small intestine. Duodenal atresia, a blockage found in 1 in 2,500 infants, often occurs in infants with Down Syndrome, according to the University of Cincinnati Hospital Medical Center.
