1. Gastro-Oesophageal Reflux Disease (GORD)

1.1 Epidemiology

• Gastro-oesophageal reflux (GOR) is extremely common, with 10–20% of adults in developed countries experiencing weekly heartburn.
• GORD is diagnosed when reflux symptoms are frequent or lead to complications (e.g. oesophagitis).
• Around 20% of patients undergoing upper GI endoscopy for upper GI symptoms have reflux oesophagitis.

1.2 Aetiology

• GORD arises from an imbalance in normal anti-reflux mechanisms, particularly involving the lower oesophageal sphincter (LOS), the Angle of Hiss, and oesophageal clearance.
• Contributory factors include:
  • Hiatus hernia (reduces LOS pressure, increases transient LOS relaxations, straightens out the Angle of Hiss).
  • Gastroparesis or delayed gastric emptying (increased gastric volume, prolonged LOS relaxations).
  • Increased intra-abdominal pressure (pregnancy, obesity).
  • Lifestyle factors: Smoking, binge drinking, high-fat meals, lying down soon after eating.
  • Certain drugs (e.g. NSAIDs) may exacerbate acid production or damage mucosa.

1.3 Pathogenesis

1. Normal Anti-Reflux Mechanisms
   • Lower Oesophageal Sphincter (LOS): A zone of higher pressure at the distal oesophagus formed by smooth circular muscle and support from the diaphragmatic crura. In health, it relaxes transiently to allow passage of food or air, and resists upward flow of gastric contents.
   • Angle of Hiss: An oblique angle at the gastro-oesophageal junction, creating an anatomical valve-like effect.
   • Oesophageal Clearance: Rapid emptying of refluxed material back into the stomach through peristaltic contractions.
2. Breakdown of Defence
   • Hiatus Hernia (especially sliding type) flattens the Angle of Hiss and compromises the LOS, promoting acid reflux.
   • Gastroparesis or delayed gastric emptying leads to increased gastric volume and prolonged LOS relaxations.
   • Increased Intra-Abdominal Pressure (e.g. obesity, pregnancy) exacerbates the pressure gradient favouring reflux.
   • Lifestyle Factors (smoking, alcohol, high-fat meals, large late-night meals) lower LOS tone or heighten transient LOS relaxations.
3. Acid-Mediated Oesophageal Damage
   • Repeated contact of the oesophageal lining with acid (± bile salts) results in local inflammation (oesophagitis).
   • Chronic injury can heal with fibrosis, potentially causing strictures or prompting metaplastic changes (Barrett’s).

1.4 Risk Factors

• Obesity or over-eating (raising intra-abdominal pressure).
• Smoking and excess alcohol (lower LOS tone, increase acid).
• Hiatus hernia (common in older patients, predisposes to reflux episodes).
• Pregnancy (increased intra-abdominal pressure).
• Late-night meals or lying down soon after eating (poor clearance of refluxed acid).

1.5 Clinical Features

• Complications:
  • Oesophagitis (from minor erythema to frank ulceration).
  • Peptic stricture (fibrotic narrowing of distal oesophagus).
  • Barrett’s oesophagus (metaplastic change predisposing to adenocarcinoma).

1.6 Diagnostic Approach

1. Clinical Assessment
   • Typically made on symptom history.
   • Investigate with endoscopy if alarm features (e.g. dysphagia, weight loss, anaemia) or if patient is middle-aged/elderly.
2. Endoscopy
   • First-line for those with alarm symptoms or refractory dyspepsia.
   • May show oesophagitis, stricture, or Barrett’s changes. Normal endoscopy does not exclude GORD (non-erosive reflux disease is common).
3. 24-hour pH Monitoring
   • Useful if the diagnosis is in doubt or surgery is considered.

1.7 Immediate Management (Conservative)

• Lifestyle Measures:
  • Weight reduction if overweight.
  • Avoid smoking and excess alcohol.
  • Small, regular meals; avoid large meals before bedtime.
  • Raise head of bed, avoid tight clothing.
• Antacids (± alginates) for symptom relief, taken as needed.

1.8 Long-Term Management

1. Pharmacological
   • H2 receptor antagonists (e.g. ranitidine) reduce acid.
   • Proton pump inhibitors (PPIs) (e.g. omeprazole, lansoprazole) provide superior symptomatic control and promote healing of oesophagitis.
     • Some patients may need long-term or on-demand PPI therapy.
   • Aim for the lowest effective dose long-term if symptoms recur upon withdrawal.
2. Endoscopic
   • Endoscopic fundoplication is still somewhat experimental for those with small or no hiatus hernia.
3. Surgical
   • Laparoscopic or open fundoplication especially for large hiatus hernias or refractory GORD.
   • Not always curative; ~60% eventually restart PPIs.
   • Potential complications (15%): dysphagia, excess flatulence, gas-bloat syndrome (inability to belch).

1.9 Prognosis / Complications

• Relapses: ~80% of people experience symptom recurrence after stopping medication, indicating a chronicnature.
• Severe oesophagitis can lead to:
  • Strictures causing dysphagia.
  • Barrett’s oesophagus (pre-malignant).
  • Adenocarcinoma of the oesophagus (rare progression, though incidence is rising).

2. Barrett’s Oesophagus

2.1 Epidemiology

• Barrett’s oesophagus involves metaplastic change in the distal oesophagus from stratified squamousepithelium to a columnar type.
• Seen in up to 8% of those with symptomatic GORD and in ~6% of asymptomatic individuals.
• Population-based screening is not routine; certain patients with chronic GORD plus multiple risk factors (e.g. >50 years old, white male, obesity, smoking, strong family history) may be considered for surveillance.

2.2 Aetiology

Barrett’s oesophagus is primarily linked to chronic gastro-oesophageal reflux exposure.

Several contributing factors drive its development:

1. Chronic GORD (Acid Reflux)
   • Repeated episodes of gastric acid reflux cause a sustained acidic environment in the lower oesophagus.
   • Over time, the persistent injury and irritation trigger an adaptive response in the oesophageal lining, prompting cells to transform into a more acid-resistant phenotype.
2. Hiatus Hernia
   • Frequently found in GORD and further increases reflux by altering the normal anatomy of the gastro-oesophageal junction.
   • The disturbed geometry reduces the competence of the lower oesophageal sphincter (LOS) and can worsen acid exposure.
3. Lifestyle and Demographic Factors
   • White males over 50 are at higher risk.
   • Obesity raises intra-abdominal pressure, favouring reflux episodes.
   • Smoking intensifies acid production and impairs LOS function, fostering an acidic environment in the distal oesophagus.
4. Metaplastic Response
   • The normal stratified squamous epithelium of the distal oesophagus is not well-suited for chronic acid contact.
   • In Barrett’s, the epithelium changes to a columnar (intestinal-type) lining better able to cope with ongoing acid stress.

2.3 Pathogenesis

1. Chronic Acidic Stress
   • The distal oesophagus is repeatedly exposed to gastric acid (and possibly bile if reflux is duodenogastro-oesophageal) due to a weakened or dysfunctional LOS.
   • This leads to ongoing inflammation and injury within the lower oesophageal mucosa.
2. Metaplastic Transformation
   • As a protective adaptation, stem cells in the oesophageal epithelium undergo reprogramming.
   • Instead of the usual stratified squamous cells, they produce a columnar epithelium containing goblet cells.
   • This new epithelium is more resistant to acid but deviates from the normal histology of the oesophagus.
3. Potential Progression to Dysplasia and Cancer
   • Metaplasia itself is reversible in principle if the driving factor (acid reflux) is removed, but in practice, Barrett’s epithelium often remains once established.
   • Persistent acid-induced damage can lead to further mutations, resulting in dysplasia and eventually adenocarcinoma.
   • While the relative risk of oesophageal adenocarcinoma is significantly higher in Barrett’s than in the general population, the absolute annual risk is low (0.1–0.4% per patient per year).

2.4 Clinical Features

• Frequently asymptomatic; many patients simply have typical GORD symptoms (e.g. heartburn, regurgitation).
• Often detected on endoscopy performed for reflux or other upper GI issues.
• No specific symptoms solely attributable to Barrett’s unless complications (like strictures) arise.

2.5 Diagnostic Approach

1. Endoscopy
   • Identifies columnar-lined oesophagus.
   • The length of involvement is recorded using the Prague criteria.
   • Multiple biopsies are taken to confirm intestinal metaplasia and to assess for dysplasia.
2. Histological Confirmation
   • Presence of columnar epithelium with goblet cells is characteristic of Barrett’s.
   • Intestinal metaplasia is the hallmark finding and the key risk factor for malignancy.

2.6 Immediate Management

• Acid-suppressive therapy (e.g. PPIs) is standard to control reflux symptoms and reduce acid exposure.
  • This does not reliably reverse the metaplastic changes but helps prevent further damage.

2.7 Long-Term Management

1. Endoscopic Surveillance
   • Frequency depends on presence/severity of dysplasia.
   • Although guidelines vary, patients with confirmed intestinal metaplasia usually undergo periodic endoscopy to detect any malignant transformation.
2. Endoscopic Ablation / Resection
   • Radiofrequency ablation (RFA) can target areas of dysplastic Barrett’s.
   • Endoscopic mucosal resection for localised high-grade dysplasia or early intramucosal carcinoma.
   • Procedures carry risks (pain, perforation, stricture formation) but can be curative for early neoplastic lesions.
3. Surgery (Oesophagectomy)
   • Considered if there is high-grade dysplasia or early cancer in patients fit enough for major surgery.
   • Remains a significant undertaking with notable morbidity.
4. Antireflux Surgery
   • (e.g. fundoplication) does not halt Barrett’s progression, but may alleviate severe GORD.

2.8 Prognosis / Complications

• Pre-malignant condition: Up to 30–fold increased relative risk of oesophageal adenocarcinoma, but the absolute risk is relatively low each year.
• Prognosis is good in most patients, though longer segments of Barrett’s, presence of dysplasia, and certain demographics significantly increase cancer risk.
• Regular follow-up with endoscopic surveillance is vital for early detection of dysplastic changes.

3. Caustic and Drug-Induced Oesophagitis

3.1 Epidemiology

• Corrosive ingestion (e.g. bleach, battery acid) is often seen in the context of deliberate self-harm. The immediate impact involves acute mucosal injury to the oropharynx and oesophagus.
• Drug-induced oesophagitis is relatively uncommon compared with other causes (like GORD or infectious oesophagitis), yet can occur in patients taking certain tablets (e.g. NSAIDs, potassium supplements, bisphosphonates) that become lodged in the oesophagus.

3.2 Aetiology

Caustic and drug-induced oesophagitis arise from direct mucosal injury by irritants:

1. Caustic (Corrosive) Ingestion
   • Substances such as bleach or battery acid cause chemical burns, leading to acute ulceration of the oropharynx and oesophagus.
   • In severe cases, immediate perforation or subsequent stricture formation can occur.
2. Drug-Induced Oesophagitis
   • Certain oral medications (e.g. NSAIDs, potassium supplements, bisphosphonates) can injure the oesophageal lining if tablets dissolve or linger above a narrowing, leading to ulceration.
   • Often related to insufficient water intake or a pre-existing oesophageal stricture causing pills to become lodged.

3.3 Pathogenesis

1. Corrosive (Caustic) Oesophagitis
   • Strong acids or alkalis (e.g. battery acid, bleach) produce intense local injury upon contact with oesophageal and oropharyngeal mucosa.
   • The agent causes chemical necrosis, ulceration, and an inflammatory response.
   • Acute risk: Perforation, mediastinitis, haemorrhage.
   • Chronic sequel: Scar tissue formation and strictures due to healing by fibrosis.
2. Drug-Induced Oesophagitis
   • Occurs when a medication (often in pill form) directly irritates or adheres to the oesophageal lining.
   • Local mucosal injury ensues, facilitated by:
     • Prolonged contact time (e.g. lying down soon after ingestion, not enough fluid intake).
     • Erosive properties of the drug (e.g. NSAIDs, bisphosphonates, K+ supplements).
   • This leads to focal ulceration or, in severe cases, deeper inflammation with possible risk of perforation or bleeding.

3.4 Risk Factors

• Corrosive ingestion:
  • Deliberate self-harm involving household chemicals (bleach) or industrial fluids (battery acid).
  • Accidental ingestion in certain occupations or by children.
• Drug-induced:
  • Known oesophageal strictures.
  • Improper pill-taking technique (insufficient water, lying supine soon after ingestion).
  • Chronic use of medications with high mucosal toxicity (e.g. certain NSAIDs, bisphosphonates, potassium supplements).

3.5 Clinical Features

1. Corrosive Oesophagitis
   • Acute: Severe oropharyngeal and retrosternal pain, possible drooling or inability to swallow (odynophagia), risk of perforation (signified by severe chest pain, mediastinal emphysema).
   • Chronic: Dysphagia can develop later due to scar-related strictures.
2. Drug-Induced Oesophagitis
   • Painful swallowing (odynophagia) or mild to severe retrosternal pain.
   • Symptoms may manifest if pills remain lodged, causing local ulceration.
   • Dysphagia may signal progression to stricture formation.

3.6 Diagnostic Approach

• Corrosive Ingestion
  • Immediate endoscopy is generally avoided initially due to the high risk of perforation and mediastinitis.
  • Later evaluation for stricture may involve endoscopy if dysphagia persists.
• Drug-Induced
  • Clinical suspicion arises from a temporal link between pill ingestion and onset of oesophageal symptoms.
  • Endoscopic examination can confirm ulcerations or identify a stricture.

3.7 Management

1. Corrosive Oesophagitis
   • Nil by mouth, analgesia, antiemetics; monitor closely for perforation.
   • In acute phases, oesophageal perforation is the major danger.
   • If strictures form subsequently, endoscopic dilatation may be attempted but is hazardous.
2. Drug-Induced Oesophagitis
   • Discontinue or modify the offending medication (alternative formulation or route).
   • Advise taking pills with plenty of water and remaining upright.
   • If severe ulceration or stricture, endoscopic evaluation and possible dilatation.

3.8 Prognosis / Complications

• Corrosive ingestion:
  • Immediate severe complications include perforation, mediastinitis, and haemorrhage.
  • Chronic complication is stricture formation, requiring dilatation or occasionally surgical intervention.
• Drug-induced:
  • Generally mild if addressed early (by stopping or changing the offending agent).
  • Persistent ulceration may cause strictures or rarely perforation.
• Endoscopic dilatation for strictures can be technically challenging and carries some risk.

4. Oesophageal Tumours

4.1 Epidemiology

• Gastrointestinal stromal tumours (GISTs) in the oesophagus are rare and usually benign, although there is a risk of malignancy (depends on tumour size and location):
  • They are often discovered incidentally during endoscopy performed for unrelated reasons.
• Oesophageal carcinoma has an overall 5-year survival of <10%:
  • Globally, the incidence patterns differ:
    • Adenocarcinoma:
      • ~5 per 100,000 in the UK (lower third of the oesophagus, associated with Barrett’s).
      • Increasing incidence in Western populations.
    • Squamous carcinoma:
      • More common worldwide, especially in Iran and the Far East.
      • Less common than adenocarcinoma in Western countries.

4.2 Aetiology

4.2.1 Gastrointestinal Stromal Tumours (GISTs)

• Benign mesenchymal tumours originating in the oesophagus.
• Usually cause no symptoms and do not require treatment unless they produce significant issues (e.g. obstructive symptoms).

4.2.2 Oesophageal Carcinoma

1. Adenocarcinoma
   • Develops in the lower third of the oesophagus.
   • Frequently linked to Barrett’s oesophagus (see separate topic) and chronic acid reflux.
2. Squamous Cell Carcinoma
   • Occurs anywhere along the oesophagus.
   • Major risk factors: smoking, alcohol, betel nut, tobacco chewing, achalasia, post-cricoid web, coeliac disease, post-corrosive injury.
3. Small Cell Carcinoma
   • Extremely rare in the oesophagus.

4.3 Pathogenesis

4.3.1 Benign GISTs

• Oesophageal GISTs (though uncommon) arise from submucosal tissue.
• In most cases, slow growth and lack of invasive behaviour mean they remain asymptomatic, found incidentally on endoscopy.
• It is associated with high rates of malignant transformation – malignant transformation depends on size and location of primary tumour:
  • Approximately 15% of the patients have metastatic disease at the time of diagnosis (peritoneum and liver).
  • Malignancy is more likely if primary tumour originates outside the stomach.

4.3.2 Oesophageal Carcinoma

1. Adenocarcinoma
   • Commonly triggered by chronic acid reflux leading to Barrett’s oesophagus (metaplasia of lower oesophageal squamous epithelium into columnar epithelium).
   • Ongoing inflammatory changes plus genetic alterations can result in malignant transformation of the metaplastic glandular cells, eventually forming an adenocarcinoma.
2. Squamous Cell Carcinoma
   • Often linked to repeated epithelial irritation (smoking, alcohol, betel nut, etc.).
   • Chronic exposure to these carcinogens induces progressive dysplasia in the squamous lining.
   • Over time, dysplastic cells accumulate genetic mutations, culminating in invasive squamous carcinoma.
3. Small Cell Carcinoma
   • Rare and aggressive tumour.

4.4 Risk Factors

1. GIST
   • Age
   • Family history
2. Oesophageal Carcinoma
   • Adenocarcinoma: Strongly associated with Barrett’s oesophagus, chronic GORD, obesity.
   • Squamous Carcinoma: Smoking, heavy alcohol intake, betel nut/tobacco chewing, achalasia, post-cricoid web, coeliac disease, prior corrosive ingestion.

4.5 Clinical Features

• Benign GISTs:
  • Commonly asymptomatic, no notable signs unless large enough to obstruct the lumen.
  • Non-specific symptoms include nausea, vomiting, abdominal discomfort, altered bowel habitus.
• Oesophageal Carcinoma:
  • Painless, rapidly progressive dysphagia (initially solids, then liquids).
  • Weight loss.
  • Chest pain or hoarseness (late, signifying local invasion).
  • Coughing after swallowing, pneumonia, or pleural effusion may indicate an oesophagobronchial fistula.
  • Bolus obstruction can occur acutely.
  • Physical exam often normal until advanced disease; cervical nodes may be palpable in late-stage disease.

4.6 Diagnostic Approach

1. GIST
   • Often found incidentally on endoscopy.
   • Biopsy performed to ascertain presence of malignant disease – will help guide treatment.
2. Oesophageal Carcinoma
   • Upper GI endoscopy: Identifies tumour site, allows biopsy for histology.
   • If endoscopic intubation is not feasible, a barium swallow can reveal the length of stricture.
   • CT scan of thorax and abdomen for staging.
   • Endoscopic ultrasound for detailed local staging (best method to assess depth and nodal involvement).

4.7 Management

4.7.1 Benign GISTs

• Localised disease – endoscopic USS with biopsy +/- surgical resection or surveillance:
  • Metastatic relapse occurs in approximately 40% of the patients.
  • Adjuvant immunotherapy (i.e. Imatinib) used in patients at high risk of metastatic relapse.
• Metastatic disease:
  • Biopsy & genotyping required to tailour treatment.
  • Treatment with immunotherapy (imatinib first-line; sunitinib second-line; regorafenib third-line; ripretinib fourth-line).
  • Debulking surgery can be performed after initial treatment with immunotherapy if responsive.

4.7.2 Oesophageal Carcinoma

1. Operable Disease (~30%):
   • Oesophagectomy (surgical resection).
   • Preoperative chemotherapy can downstage the tumour.
2. Inoperable Disease (~70%):
   • Palliation of dysphagia: Endoscopic stenting or laser.
   • Pain relief with potent analgesics.
   • Radiotherapy for squamous cancers (and occasionally adenocarcinomas) to alleviate symptoms.
   • Ensure nutritional support (oral, enteral, or parenteral as needed).

4.8 Prognosis / Complications

• GIST
  • Good prognosis as most tumours benign
  • 5-year survival for metastatic disease:
    • Localised = 95%
    • Regional = 84%
    • Distant = 52%
• Oesophageal Carcinoma
  • Overall 5-year survival <10%.
  • If tumour is operable, 5-year survival approaches 30%.
  • Late-stage presentation leads to palliative management (dysphagia stenting, analgesia).
  • Complications include stricturing, fistula formation (oesophagobronchial), local invasion to nearby structures, and malnutrition.

5. Oesophageal Motility Disorders

5.1 Epidemiology

• Manometry is crucial for diagnosing oesophageal motility disorders; the advent of high-resolution manometry has greatly improved our understanding of both normal and abnormal oesophageal physiology.
• Achalasia is a relatively rare disorder (0.5–1 per 100,000/year historically, up to 1.6 per 100,000/year in some recent reports).
  • Most commonly presents in middle age.
• Diffuse oesophageal spasm (DES) typically presents in middle age with chest pain ± dysphagia.
• Nutcracker oesophagus is another manometrically defined entity causing chest pain and dysphagia.

5.2 Aetiology

1. Achalasia
   • Degeneration of the distal oesophageal ganglia, particularly those controlling LOS relaxation.
   • May be related to disturbed nitric oxide (NO) synthesis.
   • Similar destruction of myenteric plexus is seen in Chagas’ disease (Trypanosoma cruzi infection) and oesophageal cancer (producing a ‘pseudo-achalasia’ syndrome).
2. Diffuse Oesophageal Spasm (DOS)
   • Believed to be triggered by smooth muscle spasm in response to reflux.
3. Nutcracker Oesophagus
   • Markedly high-amplitude contractions of the oesophagus.
   • Pathology is not extensively described, but results in excessive contractile force.
4. Non-Specific Motility Disorders
   • Observed in up to one-third of older patients with chest pain and dysphagia.
   • Manometric changes may not always correlate with clinical symptoms.
5. Connective Tissue Disorders
   • Systemic sclerosis can affect the oesophagus, leading to absent peristalsis and severe reflux.
   • Long-term acid injury can cause strictures if not managed.

5.3 Pathogenesis

1. Achalasia
   • Primary lesion: Degeneration of ganglion cells in the myenteric (Auerbach’s) plexus of the distal oesophagus and LOS.
   • Loss of inhibitory neurons (particularly those utilising nitric oxide) leads to failure of the LOS to relaxand absent peristalsis in the oesophageal body.
   • Over time, the oesophagus dilates proximally due to chronic obstruction at the LOS.
   • This can progress to a massively dilated, tortuous oesophagus (‘megaoesophagus’).
2. Diffuse Oesophageal Spasm
   • A hypercontractile (or discoordinated) condition in which normal peristalsis is replaced by spontaneous or simultaneous contractions triggered by acid reflux or other stimuli.
   • The exact pathophysiology is incompletely defined but is thought to involve abnormal smooth muscle hyperreactivity to oesophageal irritation.
3. Nutcracker Oesophagus
   • Characterised by excessive contractile amplitude during swallowing.
   • Mechanism suggests exaggerated neuromuscular responses, resulting in very forceful, but orderly, peristaltic waves.
4. Non-Specific Motility Disorders
   • A heterogeneous group with various manometric abnormalities (ineffective peristalsis, high/low LOS pressure).
   • Clinical significance is often uncertain, as many such findings do not reliably correlate with symptoms.
5. Systemic Sclerosis
   • Involves fibrosis and atrophy of muscular layers in the oesophagus, diminishing peristalsis.
   • LOS incompetence causes severe acid reflux, risking peptic strictures.

5.4 Risk Factors

• Achalasia:
  • Idiopathic degeneration of ganglia (main scenario).
  • Possible triggers like autoimmune influences or parasitic infection (Chagas’ disease).
• Diffuse Oesophageal Spasm:
  • Triggered by reflux or other irritants in susceptible individuals.
• Connective Tissue Disorders:
  • Systemic sclerosis can secondarily cause motility disruptions.

5.5 Clinical Features

5.5.1 Achalasia

• Dysphagia for solids and liquids from onset (progressive, debilitating).
• Regurgitation of undigested food, especially if advanced oesophageal dilatation.
• Chest pain or retrosternal discomfort.
• Heartburn (may occur despite high LOS pressure).
• Pulmonary aspiration with risk of aspiration pneumonia.
• Long-standing disease: Increased risk of squamous carcinoma of the oesophagus.

5.5.2 Diffuse Oesophageal Spasm

• Angina-like chest pain (± dysphagia), often in middle-aged patients.
• Pain episodes triggered by muscular spasm related to acid reflux or other stimuli.

5.5.3 Nutcracker Oesophagus

• Intense chest pain and occasional dysphagia.
• Caused by extremely high-amplitude contractions.

5.5.4 Non-Specific Motility Disorders

• Variable presentations of chest pain or mild dysphagia.
• Occur often in older patients; not always symptomatic.

5.5.5 Systemic Sclerosis Involvement

• Absent peristalsis in the lower oesophagus.
• Severe reflux leading to heartburn and possible peptic strictures.

5.6 Diagnostic Approach

1. Manometry
   • Key investigation for suspected motility disorders.
   • High-resolution manometry can classify achalasia subtypes (Type 1 classic, Type 2 with pressurisation, Type 3 spastic), confirm DES, or identify other patterns.
2. Barium Swallow
   • Achalasia: Bird’s beak narrowing, proximal dilatation, absent peristalsis.
   • DES: May show corkscrew oesophagus or normal if spasm is intermittent.
3. Endoscopy
   • Excludes pseudo-achalasia (e.g. carcinoma mimicking achalasia).
   • Rules out structural lesions or strictures.
4. 24-hour pH Monitoring
   • May help identify acid-triggered spasm in DES or other scenarios.

5.7 Management

5.7.1 Achalasia

• Medical
  • Calcium channel blockers, nitrates reduce LOS pressure but often have limited benefit.
• Endoscopic
  • Pneumatic dilatation: Effective in ~80% but may need repeating; ~1–2% perforation risk each time.
  • Botulinum toxin injection: Similar short-term relief but benefits usually short-lived.
  • Both approaches can provoke reflux; co-prescribe a PPI.
• Surgical
  • Heller’s myotomy (open or laparoscopic) ± partial fundoplication.
  • Suited for younger patients or those requiring multiple dilatations.
  • Reflux is common post-myotomy; hence fundoplication or PPIs may be needed.

5.7.2 Diffuse Oesophageal Spasm

• Address underlying reflux with a PPI.
• Nitrates or calcium channel blockers can reduce spasm-related pain.
• Dilatation and surgical myotomy are rarely effective.

5.7.3 Nutcracker Oesophagus

• Nitrates or calcium channel blockers to lessen contractile strength.

5.7.4 Systemic Sclerosis

• Long-term PPI therapy to manage severe reflux and prevent strictures.

5.8 Prognosis / Complications

• Achalasia:
  • Overall normal life expectancy but at risk of aspiration pneumonia, megaoesophagus, and oesophageal carcinoma (particularly squamous).
  • Up to 90% achieve good relief for ~2 years after endoscopic/surgical intervention, though repeated treatments may be required.
• Diffuse Spasm / Nutcracker:
  • Chronic conditions; management focuses on pain relief and controlling reflux if present.
  • Prognosis generally good, but symptoms can be intermittent or recurrent.
• Systemic Sclerosis:
  • Chronic progressive disease with significant morbidity from severe reflux and stricture formation if not controlled.

6. Oesophageal Endoscopic Abnormalities

6.1 Epidemiology

• Pharyngeal Pouch (Zenker’s Diverticulum)
  • Occurs primarily in elderly patients, especially males.
  • Significance: Pouch can be a source of perforation risk at endoscopy.
• Eosinophilic Oesophagitis (EoE)
  • Once thought rare; incidence now recognised as increasing (possibly ~10 per 100,000/year).
  • A leading cause of oesophageal dysphagia in both children and adults.
  • Two age peaks: childhood and early 30s; twice as common in males.
• Oesophageal Rings and Webs
  • Generally identified on radiology rather than endoscopy.
  • Schatzki’s ring: Circumferential narrowing in the mid or lower oesophagus.
  • Oesophageal webs: Typically proximal, non-circumferential.
• Mallory–Weiss Tear
  • A recognised cause of haematemesis.
  • Occurs with forceful vomiting, often after alcohol binges.

6.2 Aetiology

1. Pharyngeal Pouch
   • Incoordinate swallowing → herniation of pharyngeal mucosa through cricopharyngeus muscle (e.g. Zenker’s diverticulum).
2. Eosinophilic Oesophagitis
   • Largely an allergic disorder, with eosinophilic infiltration of the oesophageal mucosa.
   • May be part of a generalised eosinophilic gastroenteritis or occur in isolation.
3. Oesophageal Rings and Webs
   • Rings: Schatzki’s ring is a circumferential ring of mucosa/submucosa in the mid or lower oesophagus.
   • Webs: Thinner, partial folds typically found in the upper oesophagus.
   • Plummer–Vinson syndrome: Oesophageal web + iron-deficiency anaemia ± atrophic glossitis.
4. Mallory–Weiss Tear
   • Mucosal laceration of the oesophagogastric junction due to forceful vomiting or retching (often related to alcohol binges).

6.3 Pathogenesis

1. Pharyngeal Pouch
   • Incoordinate or disordered swallowing (e.g. dysfunctional cricopharyngeus) creates increased hypopharyngeal pressure, causing mucosal herniation through a weak area above the upper oesophageal sphincter.
   • Over time, a pouch forms, potentially trapping food and secretions.
2. Eosinophilic Oesophagitis
   • Considered an allergic/immune-mediated condition affecting the oesophageal mucosa.
   • Eosinophilic infiltration (≥20 eosinophils/high-power field) is triggered by allergens (food or environmental).
   • Chronic inflammation leads to oedema, ring formation, and possible stricturing if untreated.
   • Precise immunological pathways remain unclear, but likely involve Th2-type responses with involvement of interleukins and eosinophils.
3. Oesophageal Rings and Webs
   • Arise from focal structural changes in oesophageal layers (mucosa ± submucosa).
   • Rings are more distal and circumferential, potentially the result of longstanding reflux or anatomical predisposition.
   • Webs often occur proximally and may be linked with iron deficiency or other systemic factors (Plummer–Vinson syndrome).
4. Mallory–Weiss Tear
   • Forceful retching or vomiting causes a longitudinal mucosal tear at the gastro-oesophageal junction.
   • The sudden increase in intra-abdominal pressure + downward motion of the stomach leads to partial-thickness mucosal tears, potentially bleeding if submucosal vessels are involved.

6.4 Risk Factors

• Pharyngeal Pouch:
  • Older age, male gender, underlying swallowing discoordination.
• Eosinophilic Oesophagitis:
  • Allergic diathesis (e.g. other atopic diseases), certain dietary allergens, male sex, middle age or childhood onset.
• Oesophageal Rings and Webs:
  • Possibly related to chronic acid reflux (for Schatzki’s ring) and iron deficiency or autoimmune conditions (for webs).
• Mallory–Weiss Tear:
  • Heavy alcohol use, bulimia (repetitive severe retching), any condition causing violent vomiting.

6.5 Clinical Features

1. Pharyngeal Pouch
   • Dysphagia, night-time cough, halitosis, sensation of a lump in the throat, or gurgling after meals.
   • Risk of aspiration or regurgitation of undigested food.
2. Eosinophilic Oesophagitis
   • Children: Primarily vomiting.
   • Adults: Dysphagia, sometimes leading to food impaction.
   • May see typical endoscopic findings (rings, furrows, white plaques).
3. Oesophageal Rings and Webs
   • Often asymptomatic.
   • Intermittent dysphagia for solids.
   • If associated with iron-deficiency anaemia and an upper web, known as Plummer–Vinson syndrome.
4. Mallory–Weiss Tear
   • Typically presents with haematemesis following bouts of forceful retching or vomiting.
   • History often indicates initial vomitus without blood, followed by blood-streaked or frankly bloody vomitus.

6.6 Diagnostic Approach

• Pharyngeal Pouch:
  • Barium swallow is first-line if suspected (endoscopy can risk perforation if the pouch is large/unrecognised).
• Eosinophilic Oesophagitis:
  • Endoscopy with biopsy: ≥20 eosinophils/high-power field.
  • Manometry typically non-diagnostic, but 24-hour pH may rule out concomitant reflux.
• Rings/Webs:
  • Detected usually on barium swallow; endoscopy can confirm and potentially treat if needed (dilatation).
• Mallory–Weiss Tear:
  • History of violent vomiting + haematemesis.
  • Endoscopy can visualise the mucosal tear near the gastro-oesophageal junction.

6.7 Management

1. Pharyngeal Pouch
   • Surgical: Myotomy of cricopharyngeus ± resection of the pouch if symptomatic.
   • Asymptomatic or minimal symptoms: often no intervention.
2. Eosinophilic Oesophagitis
   • Dietary: Elemental or elimination diets (particularly effective in children; can help adults if adhered to).
   • PPIs: May help either by controlling reflux or through immunomodulatory effects.
   • Steroids: Systemic or topical if diet and PPIs fail.
   • Endoscopic dilatation: For strictures causing severe dysphagia.
3. Oesophageal Rings and Webs
   • If intermittent dysphagia, endoscopic dilatation is performed.
   • Address any associated condition (e.g. iron deficiency in Plummer–Vinson syndrome).
4. Mallory–Weiss Tear
   • Often self-limiting with spontaneous resolution.
   • Acid suppression (PPI) can be used if ongoing erosive injury is suspected.
   • Endoscopic intervention rarely needed unless bleeding is severe or persistent.

6.8 Prognosis / Complications

• Pharyngeal Pouch:
  • Risk of aspiration, halitosis, or rarely perforation during endoscopy.
  • Surgical correction typically curative if symptomatic.
• Eosinophilic Oesophagitis
  • Can significantly impact quality of life (especially in children).
  • Some patients may develop progressive fibrotic changes leading to strictures.
  • Long-term progression and impact remain somewhat uncertain, but repeated inflammation may lead to more narrow-calibre oesophagus or tears.
• Rings/Webs
  • Prognosis is good; asymptomatic cases require no treatment.
  • Intermittent dysphagia typically resolved by dilatation.
  • In Plummer–Vinson syndrome, iron therapy is crucial.
• Mallory–Weiss Tear
  • Prognosis excellent; most bleeds stop spontaneously.
  • Rarely, severe bleeding requires endoscopic therapy.
  • Risk of repeated tears if retching recurs.