Very few risk factors for choanal atresia have been identified. While causes are unknown, both genetic and environmental triggers are suspected. One study suggests that chemicals that act as endocrine disrupters may put an unborn infant at risk. A 2012 epidemiological study looked at atrazine, a commonly used herbicide in the U.S., and found that women who lived in counties in Texas with the highest levels of this chemical being used to treat agricultural crops were 80 times more likely to give birth to infants with choanal atresia or stenosis compared to women who lived in the counties with the lowest levels. Another epidemiological report in 2010 found even higher associations between increased incidents of choanal atresia and exposure to second-hand-smoke, coffee consumption, high maternal zinc and B-12 intake and exposure to anti-infective urinary tract medications.

This condition takes several different forms, often involving one or more fistulas connecting the trachea to the esophagus (tracheoesophageal fistula).

This condition may be visible, after about 26 weeks, on an ultrasound. On antenatal USG, the finding of an absent or small stomach in the setting of polyhydramnios was considered a potential symptom of esophageal atresia. However, these findings have a low positive predictive value. The upper neck pouch sign is another sign that helps in the antenatal diagnosis of esophageal atresia and it may be detected soon after birth as the affected infant will be unable to swallow its own saliva. Also, the newborn can present with gastric distention, cough, apnea, tachypnea, and cyanosis. In many types of esophageal atresia, a feeding tube will not pass through the esophagus.

Choanal atresia can be suspected if it is impossible to insert a nasal catheter.

Also, if one notices a continuous stream of mucus draining from one or both nostrils, it could be a sign of an atresia. Another common sign is cyanosis in an infant while breast feeding, as breathing is dependent on nasal patency in this situation.

Diagnosis is confirmed by radiological imaging, usually CT scan.

Fetal and neonatal intestinal atresia are treated using laparotomy after birth. If the area affected is small, the surgeon may be able to remove the damaged portion and join the intestine back together. In instances where the narrowing is longer, or the area is damaged and cannot be used for period of time, a temporary stoma may be placed.

Imperforate anus usually requires immediate surgery to open a passage for feces unless a fistula can be relied on until corrective surgery takes place. Depending on the severity of the imperforate, it is treated either with a perineal anoplasty or with a colostomy.

While many surgical techniques to definitively repair anorectal malformations have been described. The posterior sagittal approach (PSARP) has become the most popular. It involves dissection of the perineum without entry into the abdomen and 90% of defects in boys can be repaired this way.

When an infant is born with an anorectal malformation, it is usually detected quickly as it is a very obvious defect. Doctors will then determine the type of birth defect the child was born with and whether or not there are any associated malformations. It is important to determine the presence of any associated defects during the newborn period in order to treat them early and avoid further sequelae. There are two main categories of anorectal malformations: those that require a protective colostomy and those that do not. The decision to open a colostomy is usually taken within the first 24 hours of birth.

Sonography can be used to determine the type of imperforate anus.

The differential diagnoses are extensive and include: Alagille syndrome, alpha-1-antitrypsin deficiency, Byler disease (progressive familial intrahepatic cholestasis), Caroli disease, choledochal cyst, cholestasis, congenital cytomegalovirus disease, congenital herpes simplex virus infection, congenital rubella, congenital syphilis, congenital toxoplasmosis, cystic fibrosis, galactosemia, idiopathic neonatal hepatitis, lipid storage disorders, neonatal hemochromatosis, and total parenteral nutrition-associated cholestasis.

About 6 to 14 percent of patients who receive a routine barium swallow test of the esophagus are found to have a Schatzki ring.

A Schatzki ring is usually diagnosed by esophagogastroduodenoscopy or barium swallow. Endoscopy usually shows a ring within the lumen of the esophagus which can be of variable size (see picture). The ring is usually located a few centimetres above the gastro-esophageal junction, where the esophagus joins the stomach. Schatzki rings can often resemble a related entity called an esophageal web. Esophageal webs also contain extra mucosal tissue, but do not completely encircle the esophagus.

Endoscopies and barium swallows done for other reasons often reveal unsuspected Schatzki rings, meaning that many Schatzki rings are asymptomatic.

Two varieties of Schatzki rings have been described. The original description by Schatzki and Gary was of a ring of fibrous tissue seen on autopsy; this is the less common type of Schatzki ring. More commonly, the ring consists of the same mucosal tissue that lines the entire esophagus. Although many hypotheses have been proffered, the cause of Schatzki rings remains uncertain; both congenital and acquired factors may be involved.

Diagnosis is made by an assessment of symptoms, physical exam, and medical history, in conjunction with blood tests, a liver biopsy, and imaging. Diagnosis is often made following investigation of prolonged jaundice that is resistant to phototherapy and/or exchange transfusions, with abnormalities in liver enzyme tests. Ultrasound or other forms of imaging can confirm the diagnosis. Further testing may include radioactive scans of the liver and a liver biopsy.

It is surgically corrected, with resection of any fistula and anastomosis of any discontinuous segments.

Early treatment includes removing fluids from the stomach via a nasogastric tube, and providing fluids intravenously. The definitive treatment for duodenal atresia is surgery (duodenoduodenostomy), which may be performed openly or laparoscopically. The surgery is not urgent. The initial repair has a 5 percent morbidity and mortality rate.

Once a patient complains of dysphagia they should have an "upper endoscopy" (EGD). Commonly patients are found to have esophagitis and may have an esophageal stricture. Biopsies are usually done to look for evidence of esophagitis even if the EGD is normal. Usually no further testing is required if the diagnosis is established on EGD. Repeat endoscopy may be needed for follow up.

If there is a suspicion of a proximal lesion such as:

- history of surgery for laryngeal or esophageal cancer

- history of radiation or irritating injury

- achalasia

- Zenker's diverticulum

a "barium swallow" may be performed before endoscopy to help identify abnormalities that might increase the risk of perforation at the time of endoscopy.

If achalasia suspected an upper endoscopy is required to exclude a malignancy as a cause of the findings on barium swallow. Manometry is performed next to confirm. A normal endoscopy should be followed by manometry, and if manometry is also normal, the diagnosis is functional dysphagia.

Fistulae between the trachea and esophagus in the newborn can be of diverse morphology and anatomical location; however, various pediatric surgical publications have attempted a classification system based on the below specified types.

Not all types include both esophageal agenesis and tracheoesophageal fistula, but the most common types do.

The letter codes are usually associated with the system used by Gross, while number codes are usually associated with Vogt.

An additional type, "blind upper segment only" has been described, but this type is not usually included in most classifications.

Patients with abnormal cardiac and kidney function may be more at risk for hemolytic uremic syndrome

Intestinal atresias are often discovered before birth: either during a routine sonogram which shows a dilated intestinal segment due to the blockage, or by the development of polyhydramnios (the buildup of too much amniotic fluid in the uterus). These abnormalities are indications that the fetus may have a bowel obstruction which a more detailed ultrasound study can confirm.

Some fetuses with bowel obstruction have abnormal chromosomes. An amniocentesis is recommended because it can determine not only the sex of the baby, but whether or not there is a problem with the chromosomes.

Esophageal webs and rings can be treated with endoscopic dilation.

The patient is generally sent for a GI, pulmonary, or ENT, depending on the suspected underlying cause. Consultations with a speech therapist and registered dietitian nutritionist (RDN) are also needed, as many patients may need dietary modifications such as thickened fluids.

Atresia is a condition in which an orifice or passage in the body is (usually abnormally) closed or absent.

Examples of atresia include:

- Biliary atresia, a condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent.

- Choanal atresia, blockage of the back of the nasal passage, usually by abnormal bony or soft tissue.

- Esophageal atresia, which affects the alimentary tract and causes the esophagus to end before connecting normally to the stomach.

- Imperforate anus, malformation of the opening between the rectum and anus.

- Intestinal atresia, malformation of the intestine, usually resulting from a vascular accident in utero.

- Microtia, absence of the ear canal or failure of the canal to be tubular or fully formed (can be related to Microtia, a congenital deformity of the pinna, or outer ear).

- Ovarian follicle atresia, the degeneration and subsequent resorption of one or more immature ovarian follicles.

- Potter sequence, congenital decreased size of the kidney leading to absolutely no functionality of the kidney, usually related to a single kidney.

- Pulmonary atresia, malformation of the pulmonary valve in which the valve orifice fails to develop.

- Renal agenesis, only having one kidney.

- Tricuspid atresia, a form of congenital heart disease whereby there is a complete absence of the tricuspid valve, and consequently an absence of the right atrioventricular connection.

- Vaginal atresia, a congenital occlusion of the vagina or subsequent adhesion of the walls of the vagina, resulting in its occlusion.

The diagnosis of duodenal atresia is usually confirmed by radiography. An X-ray of the abdomen shows two large air filled spaces, the so-called "double bubble" sign. The air is trapped in the stomach and proximal duodenum, which are separated by the pyloric sphincter, creating the appearance of two bubbles visible on x-ray. Since the closure of the duodenum is complete in duodenal atresia, no air is seen in the distal duodenum.

Atresias occurring distal to the duodenum are usually caused by vascular accidents or ischemic insult, such as jejunoileal atresia.

It can be diagnosed with an X-ray while the patient swallows barium (called a barium study of the esophagus), by a computerized tomography scan, a biopsy, or by an endoscopy.

The incidence of VACTERL association is estimated to be approximately 1 in 10,000 to 1 in 40,000 live-born infants. It is seen more frequently in infants born to diabetic mothers. While most cases are sporadic, there are clearly families who present with multiple involved members.

Typically a coloboma appears oval or comet shaped with round end towards the centre. There may be a few vessels (retinal or choroidal) at the edges. The surface may have irregular depression.

If it is caused by esophagitis, in turn caused by an underlying infection, it is commonly treated by treating the infection (typically with antibiotics). In order to open the stricture, a surgeon can insert a bougie – a weighted tube used to dilate the constricted areas in the esophagus. It can sometimes be treated with other medications. For example, an H2 antagonist (e.g. ranitidine) or a proton-pump inhibitor (e.g. omeprazole) can treat underlying acid reflux disease.