There is no diagnostic gold standard for diagnosing "GERD," so diagnostics should primarily be symptom-oriented. Although diagnostic steps vary from clinic to clinic, objective morphological and functional examinations are required before surgical measures, particularly for documentation of the indication.
1. Medical History
Lower Reflux Symptoms
- Heartburn
- Belching (acidic, non-acidic)
- Retrosternal pain
- Dysphagia
- Odynophagia (pain on swallowing, rare)
Upper Reflux Symptoms
- Burning in the throat
- Regurgitation
- Chronic cough/morning throat clearing
- Hoarse voice, hoarseness
- Asthma attacks
Triggering or exacerbation of symptoms by: food intake, prolonged fasting, sweet foods, alcohol, bent body position, and lying down. Symptoms can occur episodically, intermittently, or persistently. Spontaneous remissions are possible but unlikely to be permanent.
The type, intensity, and frequency of reflux symptoms do not allow conclusions about the severity of the reflux disease or the extent of esophageal lesions.
Heartburn is the most sensitive symptom of reflux disease. If it is the main symptom, reflux is present with a probability of > 75%. If heartburn plays a minor role and other symptoms are predominant, other diseases are more likely (e.g., functional dyspepsia or ulcer). The absence of heartburn does not exclude reflux disease. Dysphagia, retrosternal discomfort, and respiratory symptoms may dominate the symptomatology in reflux disease but are still nonspecific.
During the medical history assessment, previous conservative-medication treatment should also be investigated, and any existing previous findings should be reviewed.
2. PPI Test
A complete or significant response to PPI administration suggests the presence of reflux disease, or in other words: if high-dose PPI therapy fails, the presence of GERD is unlikely.
The PPI test is only useful for symptoms that already suggest reflux disease, while endoscopy is simultaneously unremarkable. The PPI test should be conducted with two to three times the standard dosage recommended for reflux treatment over at least 2 weeks, as reflux episodes can vary from day to day without therapy or occur only intermittently.
3. Endoscopy
The importance of esophagogastroduodenoscopy in reflux diagnostics is undisputed and mandatory before surgical intervention. It enables:
- Diagnosis of reflux esophagitis and assessment of its severity (also as follow-up control in esophagitis therapy)
- Diagnosis of a hiatal hernia
- Detection of complications (stricture, ulcer)
- Exclusion of malignancy
Early endoscopy is indicated for unusually severe symptoms and alarm symptoms such as anemia, dysphagia, and weight loss. Obtaining histology is mandatory for all macroscopic abnormalities.
4. 24-Hour Esophageal pH Monitoring
The 24-hour esophageal pH monitoring is the gold standard for objectifying gastroesophageal reflux. It records the circadian rhythm of reflux episodes, physical activities, food intake, and body positions. Symptom correlation with the recorded reflux episodes is possible through patient self-documentation of symptoms, increasing the sensitivity of pH monitoring. The diagnosis of reflux esophagitis cannot be derived from the pH monitoring result; endoscopy is required for this.
A 24-hour pH monitoring is indicated for:
- Preoperative documentation of the surgical indication
- Persistence of reflux symptoms under adequate PPI medication
- In endoscopically unremarkable "NERD" patients (= Non Erosive Reflux Disease)
- Recurrent reflux symptoms after antireflux surgery
In pH monitoring, it must be noted that up to 25% of patients with reflux esophagitis and around 30% of NERD patients have normal values, which is due to the fact that even with clear reflux disease, the amount of reflux can vary from day to day.
5. Esophageal Manometry
Esophageal manometry can reliably assess the competence of the LES (resting pressure, length) and the tubular motility of the esophagus. Contraction amplitudes of the tubular esophagus below 30 mm Hg are considered hypomobile, and a resting pressure of the LES less than 5 mm Hg is considered reduced.
Esophageal manometry plays no role in the primary diagnosis of GERD but can be useful in individual cases to differentiate other esophageal motility disorders (e.g., achalasia). It is highly recommended in the context of preoperative evaluation and documentation regarding the selection of the surgical procedure. If tubular contraction disorders of the esophagus are detected, a Toupet or Nissen fundoplication should be avoided.
6. X-ray/Barium Swallow
Using barium, radiological reflux documentation can attempt to provoke reflux through provocation maneuvers (head-down and abdominal position, Valsalva maneuver). However, a sole "barium swallow" is not suitable for diagnosing GERD for the following reasons:
- Reflux is physiological, so no pathological value can be derived from the radiological representation.
- Reflux occurs intermittently and can only be reliably detected through long-term measurement, not through a radiological snapshot.
However, the barium swallow remains the gold standard for detecting an axial hiatal hernia and allows differentiation of various hernia types. Many surgeons also find the barium swallow helpful for visualizing the anatomy of the gastroesophageal junction before planned surgery.
Note:
Before antireflux surgery, endoscopy should always be performed. Before deciding on surgery, functional tests such as pH monitoring and manometry are recommended, especially for documentation of findings. If a hiatal hernia is present, its extent can be very well depicted using a barium swallow.
