Its main symptoms are pain and difficulty in swallowing (dysphagia).

Esophageal webs are thin (2-3mm) membranes of normal esophageal tissue consisting of mucosa and submucosa that can partially protrude/obstruct the esophagus. They can be congenital or acquired. Congenital webs commonly appear in the middle and inferior third of the esophagus, and they are more likely to be circumferential with a central or eccentric orifice. Acquired webs are much more common than congenital webs and typically appear in the cervical area (postcricoid).

Clinical symptoms of this condition are selective (solid more than liquids) dysphagia, thoracic pain, nasopharyngeal reflux, aspiration, perforation and food impaction (the last two are very rare).

Other birth defects may co-exist, particularly in the heart, but sometimes also in the anus, spinal column, or kidneys. This is known as VACTERL association because of the involvement of Vertebral column, Anorectal, Cardiac, Tracheal, Esophageal, Renal, and Limbs. It is associated with polyhydramnios in the third trimester.

Surgical repair can sometimes result in complications, including:

- Stricture, due to gastric acid erosion of the shortened esophagus

- Leak of contents at the point of anastomosis

- Recurrence of fistula

- Gastro-esophageal reflux disease

- Dysphagia

- Asthma-like symptoms, such as persistent coughing/wheezing

- Recurrent chest infections

- Tracheomalacia

Any attempt at feeding could cause aspiration pneumonia as the milk collects in the blind pouch and overflows into the trachea and lungs. Furthermore, a fistula between the lower esophagus and trachea may allow stomach acid to flow into the lungs and cause damage. Because of these dangers, the condition must be treated as soon as possible after birth.

In simple words, when there is excessive pressure within the lower pharynx, the weakest portion of the pharyngeal wall balloons out, forming a diverticulum which may reach several centimetres in diameter.

More precisely, while traction and pulsion mechanisms have long been deemed the main factors promoting development of a Zenker's diverticulum, current consensus considers occlusive mechanisms to be most important: uncoordinated swallowing, impaired relaxation and spasm of the cricopharyngeus muscle lead to an increase in pressure within the distal pharynx, so that its wall herniates through the point of least resistance (known as Killian's triangle, located superior to the cricopharyngeus muscle and inferior to the Thyropharyngeus muscle. Thyropharyngeus and Laryngopharyngeus are the superior and inferior parts of inferior constrictor muscle of pharynx respectively). The result is an outpouching of the posterior pharyngeal wall, just above the esophagus.

While it may be asymptomatic, Zenker diverticulum can present with the following symptoms:

- Dysphagia (difficulty swallowing), and sense of a lump in the throat

- Food might get trapped in the outpouching, leading to:

- Regurgitation, reappearance of ingested food in the mouth

- Cough, due to food regurgitated into the airway

- Halitosis, smelly breath, as stagnant food is digested by microorganisms

- Infection

It rarely, if ever, causes any pain.

Cervical webs are seen associated in 50% of patients with this condition.

Rarer forms of cervical esophageal diverticula are the Killian's diverticulum and the Laimer's diverticulum. Killian's diverticulum is formed in the Killian-Jamiseon triangle (located inferior to the cricopharyngeus on both sides of this muscle's insertion into the cricoid cartilage). Laimer's diverticulum is formed in Laimer's triangle (located inferior to the cricopharyngeus in the posterior midline above the confluence of the longitudinal layer of esophageal muscle). Laimer's triangle is covered only by the circular layer of esophageal muscle.

Esophageal diseases can derive from congenital conditions, or they can be acquired later in life.

Many people experience a burning sensation in their chest occasionally, caused by stomach acids refluxing into the esophagus, normally called heartburn. Extended exposure to heartburn may erode the lining of the esophagus, leading potentially to Barrett's esophagus which is associated with an increased risk of adenocarcinoma most commonly found in the distal one-third of the esophagus.

Some people also experience a sensation known as globus esophagus, where it feels as if a ball is lodged in the lower part of the esophagus.

The following are additional diseases and conditions that affect the esophagus:

- Achalasia

- Acute esophageal necrosis

- Barrett's esophagus

- Boerhaave syndrome

- Caustic injury to the esophagus

- Chagas disease

- Diffuse esophageal spasm

- Esophageal atresia and Tracheoesophageal fistula

- Esophageal cancer

- Esophageal dysphagia

- Esophageal varices

- Esophageal web

- Esophagitis

- GERD

- Hiatus hernia

- Jackhammer esophagus (hypercontractile peristalsis)

- Killian–Jamieson diverticulum

- Mallory-Weiss syndrome

- Neurogenic dysphagia

- Nutcracker esophagus

- Schatzki's ring

- Zenker's Diverticulum

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.

A Zenker's diverticulum, also pharyngoesophageal diverticulum, also pharyngeal pouch, also hypopharyngeal diverticulum, is a diverticulum of the mucosa of the pharynx, just above the cricopharyngeal muscle (i.e. above the upper sphincter of the esophagus). It is a pseudo diverticulum (not involving all layers of the esophageal wall).

It was named in 1877 by German pathologist Friedrich Albert von Zenker.

Not all patients with Schatzki rings have symptoms; barium swallow tests of the esophagus sometimes show Schatzki rings in patients with no swallowing difficulties.

When Schatzki rings cause symptoms, they usually result in episodic difficulties with swallowing (dysphagia) solid foods, or a sensation that the food "sticks" while swallowing, especially if the food is not chewed thoroughly. Patients usually are able to regurgitate or force through the food material and resume eating. However, complete obstruction of the esophagus by a bolus of food (often called steakhouse syndrome) can occur. This can cause crushing chest pain and may need immediate treatment with endoscopy, which is the use of a specialized fibre-optic camera in order to remove the lodged food. After the obstruction is located, snares or forceps are inserted to pull the food out of the esophagus or to push it into the stomach. The latter is done with caution, usually when the anatomy of the structures around the obstruction is already known.

Esophageal stricture, or narrowing of the esophagus, is usually a complication of acid reflux, most commonly due to gastroesophageal reflux (GERD). These patients are usually older and have had GERD for a long time. Esophageal stricture can also be due to other causes, such as acid reflux from Zollinger-Ellison syndrome, trauma from a nasogastric tube placement, and chronic acid exposure in patients with poor esophageal motility from scleroderma. Other non-acid related causes of peptic strictures include infectious esophagitis, ingestion of chemical irritant, pill irritation, and radiation. Peptic stricture is a progressive mechanical dysphagia, meaning patients will complain of initial intolerance to solids followed by inability to tolerate liquids. When the diameter of the stricture is less than 12 mm the patient will always have dysphagia, while dysphagia is not seen when the diameter of the stricture is above 30 mm. Symptoms relating to the underlying cause of the stricture usually will also be present.

Esophageal cancer also presents with progressive mechanical dysphagia. Patients usually come with

rapidly progressive dysphagia first with solids then with liquids, weight loss (> 10 kg), and anorexia (loss of appetite). Esophageal cancer usually affects the elderly. Esophageal cancers can be either squamous cell carcinoma or adenocarcinoma. Adenocarcinoma is the most prevalent in the US and is associated with patients with chronic GERD who have developed Barrett's esophagus (intestinal metaplasia of esophageal mucosa). Squamous cell carcinoma is more prevalent in Asia and is associated with tobacco smoking and alcohol use.

Esophageal rings and webs, are actual rings and webs of tissue that may occlude the esophageal lumen.

- "Rings" --- Also known as Schatzki rings from the discoverer, these rings are usually mucosal rings rather than muscular rings, and are located near the gastroesophageal junction at the squamo-columnar junction. Presence of multiple rings may suggest eosinophilic esophagitis. Rings cause intermittent mechanical dysphagia, meaning patients will usually present with transient discomfort and regurgitation while swallowing solids and then liquids, depending on the constriction of the ring.

- "Webs" --- Usually squamous mucosal protrusion into the esophageal lumen, especially anterior cervical esophagus behind the cricoid area. Patients are usually asymptomatic or have intermittent dysphagia. An important association of esophageal webs is to the Plummer-Vinson syndrome in iron deficiency, in which case patients will also have anemia, koilonychia, fatigue, and other symptoms of anemia.

Achalasia is an idiopathic motility disorder characterized by failure of lower esophageal sphincter (LES) relaxation as well as loss of peristalsis in the distal esophagus, which is mostly smooth muscle. Both of these features impair the ability of the esophagus to empty contents into the stomach. Patients usually complain of dysphagia to both solids and liquids. Dysphagia to liquids, in particular, is a characteristic of achalasia. Other symptoms of achalasia include regurgitation, night coughing, chest pain, weight loss, and heartburn. The combination of achalasia, adrenal insufficiency, and alacrima (lack of tear production) in children is known as the triple A (Allgrove) syndrome. In most cases the cause is unknown (idiopathic), but in some regions of the world, achalasia can also be caused by Chagas disease due to infection by "Trypanosoma cruzi".

Scleroderma is a disease characterized by atrophy and sclerosis of the gut wall, most commonly of the distal esophagus (~90%). Consequently, the lower esophageal sphincter cannot close and this can lead to severe gastroesophageal reflux disease (GERD). Patients typically present with progressive dysphagia to both solids and liquids secondary to motility problems or peptic stricture from acid reflux.

Spastic motility disorders include diffuse esophageal spasm (DES), nutcracker esophagus, hypertensive lower esophageal sphincter, and nonspecific spastic esophageal motility disorders (NEMD).

- "DES" can be caused by many factors that affect muscular or neural functions, including acid reflux, stress, hot or cold food, or carbonated drinks. Patients present with intermittent dysphagia, chest pain, or heartburn.

Rare causes of esophageal dysphagia not mentioned above

- Diverticulum

- Aberrant subclavian artery, or (dysphagia lusoria)

- Cervical osteophytes

- Enlarged aorta

- Enlarged left atrium

- Mediastinal tumor

The change from normal to premalignant cells that indicate Barrett's esophagus does not cause any particular symptoms. Barrett's esophagus, however, is associated with these symptoms:

- frequent and longstanding heartburn

- trouble swallowing (dysphagia)

- vomiting blood (hematemesis)

- pain under the sternum where the esophagus meets the stomach

- unintentional weight loss because eating is painful (odynophagia)

The risk of developing Barrett's esophagus is increased by central obesity (vs. peripheral obesity). The exact mechanism is unclear. The difference in distribution of fat among men (more central) and women (more peripheral) may explain the increased risk in males.

Patients usually complain of dysphagia (the feeling of food getting stuck "several seconds" after swallowing), and will point to the suprasternal notch or behind the sternum as the site of obstruction.

Diverticula may occur in one of the three areas of the esophagus - the pharyngoesophageal, the midesophageal area or the epiphrenic area of esophagus. Zenker's diverticulum is found three times more frequently in men than in women. It occurs posteriorly through the cricopharyngeal muscle in the midline of the neck. Usually seen in people older than 60 years of age.

- Gastric diverticula - "Although usually asymptomatic, they may cause vague epigastric pain. These lesions may be confused radiologically for gastric ulcers or cancers. Endoscopically, they may be confused for paraesophageal hernias."

- Killian-Jamieson diverticulum

- Meckel's diverticulum: a persistent portion of the omphalomesenteric duct present in 2% of the population

- Rokitansky-Aschoff sinuses: in the gallbladder due to chronic cholecystitis

- Traction esophageal diverticulum: due to scarring from mediastinal or pulmonary tuberculosis

- Urethral diverticulum: congenital in males, post-infectious in females

- Zenker's diverticulum: a diverticulum of the mucosa of the pharynx affecting adults

Most of these pathological types of diverticulum are capable of harboring an enterolith. If the enterolith stays in place, it may cause no problems, but a large enterolith expelled from a diverticulum into the lumen can cause obstruction.

Esophageal webs are thin membranes occurring anywhere along the esophagus.

A Schatzki ring or Schatzki–Gary ring is a narrowing of the lower esophagus that can cause difficulty swallowing (dysphagia). The narrowing is caused by a ring of mucosal tissue (which lines the esophagus) or muscular tissue. A Schatzki ring is a specific type of "esophageal ring", and Schatzki rings are further subdivided into those above the esophagus/stomach junction (A rings), and those found at the squamocolumnar junction in the lower esophagus (B rings).

Patients with Schatzki rings can develop intermittent difficulty swallowing or, more seriously, a completely blocked esophagus. The ring is named after the German-American physician Richard Schatzki.

Barrett's esophagus refers to an abnormal change (metaplasia) in the cells of the lower portion of the esophagus. It is characterized by the replacement of the normal stratified squamous epithelium lining of the esophagus by simple columnar epithelium with goblet cells (which are usually found lower in the gastrointestinal tract). The medical significance of Barrett's esophagus is its strong association (0.1 per 1 cm Prague C>M> total segment length per patient-year) with esophageal adenocarcinoma, a very often deadly cancer, because of which it is considered to be a premalignant condition.

The main cause of Barrett's esophagus is thought to be an adaptation to chronic acid exposure from reflux esophagitis. The incidence of esophageal adenocarcinoma has increased substantially in the Western world in recent years. The condition is found in 5–15% of patients who seek medical care for heartburn (gastroesophageal reflux disease), although a large subgroup of patients with Barrett's esophagus do not have symptoms. Diagnosis requires endoscopy (more specifically, esophagogastroduodenoscopy, a procedure in which a fibreoptic cable is inserted through the mouth to examine the esophagus, stomach, and duodenum) and biopsy. The cells of Barrett's esophagus, after biopsy, are classified into four general categories: nondysplastic, low-grade dysplasia, high-grade dysplasia, and frank carcinoma. High-grade dysplasia and early stages of adenocarcinoma can be treated by endoscopic resection and new endoscopic therapies such as radiofrequency ablation, whereas advanced stages (submucosal) are generally advised to undergo surgical treatment. Nondysplastic and low-grade patients are generally advised to undergo annual observation with endoscopy, with radiofrequency ablation as a therapeutic option. In high-grade dysplasia, the risk of developing cancer might be at 10% per patient-year or greater.

The condition is named after the Australian-born British thoracic surgeon Norman Barrett (1903–1979), who described it in 1950.

Those with the eating disorder bulimia are more likely to develop Barrett’s esophagus because bulimia can cause severe acid reflux, and because purging also floods the esophagus with acid.

Diverticula are described as being true or false depending upon the layers involved:

- True diverticula involve all layers of the structure, including muscularis propria and adventitia, such as Meckel's diverticulum.

- False diverticula (also known as "pseudodiverticula") do not involve muscular layers or adventitia. False diverticula, in the GI tract for instance, involve only the submucosa and mucosa.

There are other forms of anorectal malformations though imperforate anus is most common. Other variants include anterior ectopic anus. This form is more commonly seen in females and presents with constipation.

Imperforate anus is associated with an increased incidence of some other specific anomalies as well, together being called the VACTERL association:

- V – Vertebral anomalies

- A – "Anal atresia"

- C – Cardiovascular anomalies

- T – Tracheoesophageal fistula

- E – Esophageal atresia

- R – Renal (kidney) and/or radial anomalies

- L – Limb defects

Other entities associated with an imperforate anus are trisomies 18 and 21, the cat-eye syndrome (partial trisomy or tetrasomy of a maternally derived number 22 chromosome), Baller-Gerold syndrome, Currarino syndrome, caudal regression syndrome, FG syndrome, Johanson-Blizzard syndrome, McKusick-Kaufman syndrome, Pallister-Hall syndrome, short rib-polydactyly syndrome type 1, Townes-Brocks syndrome, 13q deletion syndrome, urorectal septum malformation sequence, and the OEIS complex (omphalocele, exstrophy of the cloaca, imperforate anus, spinal defects).

Symptoms of esophageal strictures include heartburn, bitter or acid taste in the mouth, choking, coughing, shortness of breath, frequent burping or hiccups, pain or trouble swallowing, throwing up blood, or weight loss.

Symptoms depend on the location of the duplication. Duplications occurring high in the gastrointestinal tract (e.g. esophageal) may cause difficulty breathing due to compression of the airway. Lower gastrointestinal duplications (e.g. duodenum, colon) can be associated with abdominal pain, gastrointestinal bleeding, a palpable mass, vomiting, or may cause bowel obstruction. Smaller lesions can act as a so-called "lead point" for intussusception.

A Killian–Jamieson diverticulum is an outpouching of the esophagus just below the upper esophageal sphincter.

The physicians that first discovered the diverticulum were Gustav Killian and James Jamieson. Diverticula are seldom larger than 1.5 cm, and are less frequent than the similar Zenker's diverticula. As opposed to a Zenker's, which is typically a posterior and inferior outpouching from the esophagus, a Killian–Jamieson diverticulum is typically an anterolateral outpouching at the level of the C5-C6 vertebral bodies, due to a congenital weakness in the cervical esophagus just below the cricopharyngeal muscle. It is usually smaller in size than a Zenker's diverticulum, and typically asymptomatic. Although congenital, it is more commonly seen in elderly patients.

It can be caused by or associated with gastroesophageal reflux disease, esophagitis, a dysfunctional lower esophageal sphincter, disordered motility, lye ingestion, or a hiatal hernia. Strictures can form after esophageal surgery and other treatments such as laser therapy or photodynamic therapy. While the area heals, a scar forms, causing the tissue to pull and tighten, leading to difficulty in swallowing.

Laryngeal cleft is usually diagnosed in an infant after they develop problems with feeding, such as coughing, cyanosis (blue lips) and failing to gain weight over time. Pulmonary infections are also common. The longer the cleft, the more severe are the symptoms. Laryngeal cleft is suspected after a video swallow study (VSS) shows material flowing into the airway rather than the esophagus, and diagnosis is confirmed through endoscopic examination, specifically microlaryngoscopy and bronchoscopy. If a laryngeal cleft is not seen on flexible nasopharyngoscopy, that does not mean that there is not one there. Laryngeal clefts are classified into four types according to Benjamin and Inglis. Type I clefts extend down to the vocal cords; Type II clefts extend below the vocal cords and into the cricoid cartilage; Type III clefts extend into the cervical trachea and Type IV clefts extend into the thoracic trachea. Subclassification of type IV clefts into Type IVA (extension to 5 mm below the innomate artery) and Type IV B (extension greater than 5 mm below the innominate artery) may help with preoperative selection of those who can be repaired via transtracheal approach (Type IV A) versus a cricotracheal separation approach (type IV B).

Enteric duplication cysts, sometimes simply called duplication cysts, are rare congenital malformations of the gastrointestinal tract. They most frequently occur in the small intestine, particularly the ileum, but can occur anywhere along the gastrointestinal tract. They may be cystic or tubular in conformation.

The condition of having duplication cysts has been called intestinal duplication.