Examination of the esophagus: diagnosis of symptoms and complaints

The primary indications for referral for esophageal examination include persistent dysphagia, a sensation of food impaction, non-cardiac chest pain, heartburn with insufficient response to therapy, vomiting, unexplained anemia, weight loss, and signs of bleeding. These symptoms correlate with pathologies requiring confirmation by visual and functional testing, and when combined with "red flags," they prompt a more rapid route to endoscopy. [1]

Red flags include progressive dysphagia, odynophagia, hematemesis or melena, unexplained weight loss, iron deficiency anemia, and new-onset dysphagia in patients over 50 years of age. When these are present, early esophagogastroduodenoscopy is preferred because it allows for simultaneous diagnosis and treatment of strictures, tumors, or foreign bodies. [2]

In immunocompetent patients with unexplained retrosternal dysphagia, barium fluoroscopy is acceptable for initial imaging. However, if perforation is suspected, a water-soluble agent should be the primary contrast agent. This practice reduces the risk of mediastinitis and is consistent with current radiological quality parameters. [3]

If complaints point to gastroesophageal reflux disease, and endoscopy reveals no erosions, outpatient reflux monitoring with pH or pH-impedance according to the modern Lyon 2.0 criteria becomes the "gold standard." This allows one to distinguish "proven" reflux from "unproven" and choose further tactics. [4]

Table 1. Indications and “red flags” for urgent diagnosis of the esophagus

Situation	Preferred first test	Notes on urgency
Progressive dysphagia, odynophagia	Esophagogastroduodenoscopy	Rapid referral to rule out tumor and stricture
Iron deficiency anemia, melena, hematemesis	Esophagogastroduodenoscopy	Diagnosis and possible hemostasis
Chest pain of non-cardiac origin	Esophagogastroduodenoscopy or pH-impedance in normal endoscopy	Rule out esophagitis and reflux-related pain
Suspected perforation	Fluoroscopy with water-soluble contrast and CT as indicated	Water-soluble contrast as the first step
Refractory heartburn with normal endoscopy	Ambulatory pH or pH impedance monitoring	According to Lyon 2.0, determine the evidence of reflux

Esophagogastroduodenoscopy: the basis of visual diagnostics

Esophagogastroduodenoscopy remains the primary method for assessing the esophageal mucosa and lumen. It allows for the visualization of esophagitis, infectious lesions, strictures, and neoplasms, as well as performing biopsies and dilations in cases of strictures. In cases of dysphagia, endoscopy is recommended as the first-line test, as it combines diagnosis and treatment in a single session. [5]

If Barrett's esophagus is suspected, a standardized "Seattle" biopsy protocol is used: if dysplasia is absent, biopsies are taken in four quadrants every 2 cm; if dysplasia is present or suspected, biopsies are taken every 1 cm, with mandatory targeted sampling of all lesions. This approach increases the detection of dysplasia and early adenocarcinoma. [6]

Evaluation of patients with eosinophilic esophagitis requires multiple biopsies, even if the endoscopic findings are normal. Current guidelines emphasize the need for at least six biopsies from at least two levels, such as the distal and proximal or midsection, with targeted sampling from areas with typical endoscopic findings. [7]

In a number of clinical situations, it is advisable to use the FLIP functional sensor during endoscopy to assess the distensibility of the esophagogastric junction. This technology complements manometry, helps confirm achalasia with characteristic endoscopic findings, and assesses the mechanical basis of persistent dysphagia after interventions. [8]

Table 2. Basic diagnostic methods for the esophagus: purpose, what they reveal, key advantages and limitations

Method	What does it show?	Key benefits	Restrictions
Esophagogastroduodenoscopy	Mucosa, strictures, neoplasms	Diagnosis and treatment in one session, biopsy	Does not assess motor skills, requires preparation
Barium fluoroscopy	Lumen, strictures, diverticula, bolus retention	Visualization of swallow and transit dynamics	Does not provide histology
Timed barium esophagography	Quantitative barium retention in minutes	Objective assessment of bowel movements	There is no single protocol outside of standardization
High-resolution manometry	Peristalsis and relaxation of the lower sphincter	Diagnosis of achalasia and other motor disorders	Catheter procedure does not show mucous membrane
Ambulatory pH or pH impedance	Acid and non-acid reflux and its relationship to symptoms	Confirms or excludes reflux according to Lyon 2.0	Requires adherence to the "on" or "off" IPP protocol
FLIP	Real-time stretchability and diameter	Useful in controversial cases of obstruction	Does not replace manometry and does not diagnose GERD.

Radiological methods: from biphasic esophagography to timed assessment of emptying

Conventional biphasic esophagography is useful for identifying strictures, diverticula, and transit disorders, particularly if dysphagia is unclear or mixed. This method complements endoscopy and can precede it in complex anatomical situations. If there is a risk of perforation, a water-soluble contrast agent is always used first, and then, if the test is negative, a transition to barium is permitted. [9]

Timed barium esophagography standardizes the measurement of bolus retention. The patient drinks 200 ml of low-density barium, and images are taken standing at 1, 2, and 5 minutes, with column height measured. A threshold of greater than 2 cm at 5 minutes supports the diagnosis of achalasia and helps differentiate it from junctional obstruction and functional disorders. The combination of liquid barium and a barium tablet improves diagnostic accuracy. [10]

The method is particularly valuable for objectively assessing the outcome of achalasia treatment after pneumatic dilation, myotomy, or pomectomy. Changes in the area or height of the column between the initial study and the control correlate with the risk of symptom recurrence and allow for standardized monitoring. [11]

If perforation is suspected, especially after interventions, in addition to fluoroscopy, computed tomography of the neck and chest with contrast is indicated. This approach expedites the verification of leakage and complications. [12]

Table 3. Timed barium esophagography: practical protocol and interpretation

Stage	Standard action	Interpretation criterion
Preparation	Be on an empty stomach, explain the test	Reducing the risk of aspiration
Contrast reception	200 ml of low-density barium in a standing position	Uniformity of volume for comparability
Photos	Frontal projections after 1, 2, 5 minutes	Measuring the height of a pole in centimeters
Delay criterion	A height greater than 2 cm at 5 minutes supports the diagnosis of achalasia.	Increases sensitivity and specificity
Additions	Barium tablet for suspected junctional obstruction	Increased diagnostic information content

Functional diagnostics of motor skills: high-resolution manometry and FLIP

High-resolution manometry is the standard for diagnosing esophageal motility disorders, including three subtypes of achalasia and hypo- or hypermotility disorders. Current interpretation is based on the Chicago Classification version 4.0, which clarifies criteria for junctional relaxation disorders and proposes provocative tests to assess contractile reserves. [13]

Manometry is indicated for unexplained dysphagia after mechanical obstruction has been ruled out, in preparation for antireflux surgery, in cases of ineffective proton pump inhibitor therapy in patients with "unproven" reflux, and to differentiate spastic disorders. The results directly influence treatment strategy and prognosis. [14]

Functional assessment of FLIP compliance is performed during endoscopy and is helpful when manometry is unavailable or yields inconclusive results. A normal FLIP junction opening has a high negative predictive value for obstruction at the junction, whereas marked rigidity confirms the functional nature of the obstruction. [15]

Following invasive upper gastrointestinal procedures, FLIP is useful for assessing the causes of persistent dysphagia and verifying the adequacy of myotomy in achalasia. It should be noted that FLIP is not used to diagnose gastroesophageal reflux disease and does not replace manometry. [16]

Diagnosis of gastroesophageal reflux disease: Lyon 2.0 criteria and choice of monitoring

The Lyon 2.0 criteria formalized the concepts of "proven reflux" and "unproven reflux" and set thresholds for acid exposure time, including extended studies of up to 96 hours for a wireless pH capsule. This increased diagnostic specificity and allowed for personalized therapy selection. [17]

In the absence of erosive esophagitis on endoscopy and before the initiation of long-term antisecretory therapy, outpatient monitoring is performed "off" therapy to confirm reflux. In cases of "proven" reflux with persistent symptoms, pH-impedance monitoring is performed "on" therapy to assess acidic and non-acidic episodes and their relationship to complaints. [18]

The recognition of erosive esophagitis grade B according to the Los Angeles classification as “proof” of reflux is one of the key innovations of Lyon 2.0. This reduces the need for monitoring in some patients and speeds up decision-making. [19]

Extended wireless studies of up to 96 hours increase sensitivity for fluctuating reflux profiles, but the optimal duration may depend on the clinical objective and tolerability. The decision is made individually, taking into account the thresholds and metrics outlined by consensus. [20]

Table 4. Lyon 2.0: Practical thresholds and tactics for reflux monitoring

Scenario	What kind of monitoring?	Key threshold
Unproven reflux, no erosions	pH or pH impedance "outside" therapy	Acid exposure time greater than 6% confirms the disease
Proven reflux and persistent symptoms	pH impedance “on” therapy	The relationship of symptoms with reflux episodes determines the tactics
Questionable picture of reflux	Extended Wireless pH Capsule up to 96 hours	Increases diagnostic confidence

Eosinophilic esophagitis: diagnostic criteria and biopsy protocol

The diagnosis is based on symptoms of esophageal dysfunction and histology with eosinophil count. A threshold of 15 eosinophils per high-power field, combined with the exclusion of alternative causes of inflammation, remains the standard for verification. In the era of modern guidelines, a trial of discontinuation or initiation of proton pump inhibitors serves as a tactical treatment step rather than a requirement for diagnosis. [21]

To increase sensitivity, at least six biopsies should be taken from at least two levels, preferably from areas with signs of activity on endoscopy. This approach takes into account the "patchy" nature of infiltration and reduces the risk of false-negative results. [22]

Even with a normal endoscopic appearance of the mucosa, biopsies are mandatory, since up to 10% of patients have a macroscopically "quiet" esophagus with active inflammation based on histology. The addition of FLIP is useful for assessing rigidity and remodeling in stricturing esophagus. [23]

Standardized protocols for eosinophil collection and counting improve compliance and comparability of observations, particularly in pediatric practice. [24]

Table 5. Eosinophilic esophagitis: what, where and how much to take

Component	Recommendation
Number of fragments	At least 6
Fence levels	Minimum two: distal and proximal or middle
Targeted biopsies	From areas of edema, furrows, exudate, and tracheal relief
Histology threshold	15 or more eosinophils per high power field
Repeat biopsies	To monitor response and if symptoms change

Barrett's esophagus: screening, mapping, and surveillance intervals

Screening with standard endoscopy may be considered in individuals with several risk factors, including male gender, age over 50, obesity, smoking, long-standing reflux, and a family history of Barrett's or adenocarcinoma. For "noninvasive" coverage expansion, the use of cell collectors may be considered at the discretion of the center. [25]

If endoscopic suspicion is present, the diagnosis is confirmed histologically and the Seattle protocol for mapping is used, as described above. This remains the standard for tissue sampling in the context of modern visual enhancement technologies. [26]

Observation intervals depend on the segment length and the presence of dysplasia. For the non-dysplastic variant, a range of 3-5 years is typically used for a short segment and 2-3 years for a segment of 3 cm or more, with shorter intervals in cases of "uncertainty" regarding dysplasia and confirmed low-grade dysplasia. National recommendations and route adaptation tools are regularly updated. [27]

High-grade dysplasia and early carcinoma are indications for endoscopic treatment with close follow-up. Adequate mapping reduces the risk of missing lesions and increases oncological vigilance. [28]

Table 6. Observation of Barrett's esophagus: interval guidelines

Situation	Recommended observation interval
Non-dysplastic segment less than 3 cm	Endoscopy every 3-5 years
Non-dysplastic segment 3 cm or more	Endoscopy every 2-3 years
"Uncertainty" about dysplasia	Repeat endoscopy after 6-12 months with optimization of acid suppression
Confirmed low grade dysplasia	Enhanced surveillance or endoscopic ablation as indicated
After endoscopic treatment of dysplasia	Intensive monitoring for the first 12 months, then annually according to the center's schedule

Emergencies: foreign bodies, chemical burns, perforation

Foreign bodies and impacted food boluses require rapid endoscopic evacuation, especially in cases of complete obstruction and aspiration risk. Current European guidelines emphasize timeliness, adequate sedation, the use of protective devices, and the selection of instruments based on the object. [29]

In chemical burns, the primary focus is on assessing severity and complications, and early endoscopy helps to stratify risk and plan management, but is performed cautiously and as indicated. Delayed strictures require subsequent endoscopic treatment. [30]

Suspected perforation dictates the "water-soluble contrast first" algorithm, followed by CT scanning if necessary. This protocol minimizes complications and expedites decision making. [31]

After endoscopic interventions, early dysphagia is often associated with edema or local leakage, where fluoroscopy with water-soluble contrast and computed tomography show the greatest diagnostic value. [32]

Table 7. "How to choose a test": quick routes for typical complaints

Complaint	A mechanical cause is likely	Motor disorder is likely	A probable first step
Solid food gets stuck, progression	Yes	Possible	Endoscopy with biopsy and possible dilation
Both solid and liquid food, alternately	Maybe	Yes	High-resolution manometry after exclusion of mechanics
Heartburn with normal endoscopy	No	No	Outpatient monitoring with Lyon 2.0 "outside" therapy
After intervention, suspected leak	Yes	No	Fluoroscopy with water-soluble contrast and computed tomography as indicated
Suspected achalasia	No	Yes	High-resolution manometry and timed barium esophagography

Preparation and Safety

Preparation for endoscopy includes fasting, review of anticoagulant therapy as indicated, and an anesthesia management plan. When planning FLIP, standard sedation regimens that do not distort compliance measurements are preferred. For manometry, information is provided on nasal catheter tolerance and the need to temporarily discontinue certain medications that affect motility. [33]

For fluoroscopy and timed voiding assessment, consistent contrast volumes and positioning are essential, and airway protection measures are used if there is a risk of aspiration. Standardization of protocols improves reproducibility and comparability of results between centers. [34]

If perforation is suspected, water-soluble contrast is used initially; barium is only acceptable after a negative test. This rule reduces the risk of chemical mediastinitis and is consistent with quality parameters in radiology. [35]

The choice of diagnostic route should take into account the Lyon 2.0 criteria and the Chicago Classification version 4.0, since they set the thresholds and language for describing reflux and motility, on the basis of which decisions are made about therapy and the scope of observation. [36]