上部消化管（GI）疾患は、消化と栄養吸収の中枢器官である食道、胃、十二指腸に影響を与えます。疾患は広範なもの（GERDは世界の成人の約40%に影響）から複雑なもの（バレット食道、消化性潰瘍疾患、食道狭窄）まで多岐にわたります。診断は主に上部GI内視鏡検査（胃内視鏡検査/OGD）に依存しており、直接的な粘膜可視化、生検能力、バルーン拡張・止血・アブレーションなどの治療的介入へのアクセスを提供します。本ガイドは、BSG、ESGE、グローバル消化器科ガイドラインに沿った主要な上部GI疾患、内視鏡処置、治療戦略を網羅しています。
Overview of Upper GI Diseases
The upper gastrointestinal (GI) tract includes the oesophagus, stomach, and the first part of the small intestine (duodenum). Diseases affecting these organs are among the most common medical conditions worldwide, ranging from reflux and ulcers to more serious conditions like Barrett's oesophagus and oesophageal cancer.
Many upper GI conditions are manageable with lifestyle changes and medication, but some require endoscopic or surgical intervention. Early diagnosis is key — a gastroenterologist uses a thin flexible camera (endoscope) passed through the mouth to visualise the lining of the oesophagus, stomach, and duodenum.
When to see a doctor
Persistent heartburn, difficulty swallowing, unexplained weight loss, vomiting blood, or dark tarry stools are all symptoms that require prompt medical evaluation.
Upper GI pathology spans a spectrum from functional disorders (functional dyspepsia, non-erosive reflux disease) to structural and neoplastic disease. Accurate classification drives appropriate investigation and therapy selection. The Rome IV criteria guide functional GI disorder diagnosis. Upper GI endoscopy (oesophagogastroduodenoscopy, OGD) remains the gold standard for direct mucosal visualisation, biopsy, and therapeutic intervention.
| Condition | Category | Primary Investigation | Endoscopy Role |
|---|---|---|---|
| GERD / NERD | Functional / Structural | 24h pH-impedance, OGD | Diagnostic (LA classification), surveillance |
| Peptic Ulcer Disease | Structural | OGD + H. pylori testing | Diagnosis, biopsy, haemostasis |
| Barrett's Oesophagus | Pre-neoplastic | OGD + biopsy (Prague criteria) | Surveillance, RFA, EMR, ESD |
| Oesophageal Stricture | Structural | OGD, barium swallow | Dilation (balloon / bougie), stenting |
| Oesophageal Cancer | Neoplastic | OGD + biopsy, CT staging | Diagnosis, EUS, stenting, palliation |
| Gastric Cancer | Neoplastic | OGD + biopsy, CT/PET | Diagnosis, ESD, palliation |
Anatomy of the Upper GI Tract
Oesophagus
A muscular tube (~25 cm) connecting the throat to the stomach. Lined by squamous epithelium; propels food by peristalsis. The lower oesophageal sphincter (LOS) prevents acid reflux.
Stomach
Stores and partially digests food using hydrochloric acid and pepsin. Lined by gastric mucosa; the antrum produces gastrin. Capacity ~1 litre when full.
Pylorus
The gateway between stomach and duodenum. Controls the rate of gastric emptying. Pyloric stenosis (narrowing) can cause persistent vomiting.
Duodenum
The first 25–30 cm of the small intestine. Receives bile and pancreatic enzymes; the most common site of peptic ulcers. The ampulla of Vater opens here.
Clinical Note — Gastro-oesophageal Junction (GOJ)
The GOJ (Z-line / squamocolumnar junction) is the critical landmark in upper GI endoscopy. Its precise identification using the Prague C&M criteria is essential for Barrett's staging. The lower oesophageal sphincter (LOS) and the diaphragmatic hiatus normally coincide; in hiatus hernia they separate, impairing the anti-reflux barrier. The Hill grade and BRAVO pH capsule placement both reference this landmark. During OGD, retroflexion in the stomach allows inspection of the gastric cardia and fundus — areas missed on forward view.
Gastro-oesophageal Reflux Disease (GERD)
GERD occurs when stomach acid repeatedly flows back into the oesophagus, irritating its lining. It is one of the most common digestive disorders globally, affecting approximately 1 in 5 adults in Western countries.
Occasional heartburn is normal. GERD is diagnosed when symptoms are frequent (more than twice per week), persistent, or when they cause complications such as erosions, strictures, or Barrett's oesophagus.
Symptoms
Typical Symptoms
- Heartburn — burning sensation behind the breastbone
- Regurgitation of acid or food into the mouth
- Chest discomfort, especially after eating
- Difficulty swallowing (dysphagia)
- Sensation of a lump in the throat (globus)
Atypical / Extra-oesophageal Symptoms
- Chronic cough or throat clearing
- Hoarseness / laryngitis
- Asthma exacerbation
- Dental erosion from acid
- Non-cardiac chest pain
Risk Factors
LA Classification of Oesophagitis (OGD Grading)
| Grade | Endoscopic Findings | Management |
|---|---|---|
| A | One or more mucosal breaks ≤5 mm, not extending between mucosal folds | PPI 4–8 weeks; lifestyle modification |
| B | One or more mucosal breaks >5 mm, not continuous between folds | PPI 8 weeks; consider maintenance |
| C | Mucosal breaks continuous between ≥2 folds but <75% circumference | PPI maintenance; Barrett's surveillance |
| D | Mucosal breaks involving ≥75% of oesophageal circumference | High-dose PPI; urgent Barrett's surveillance; surgical referral |
Peptic Ulcer Disease (PUD)
A peptic ulcer is an open sore that develops on the inner lining of the stomach (gastric ulcer) or the upper part of the small intestine (duodenal ulcer). They form when the protective mucus layer is disrupted, allowing acid to damage the tissue underneath.
The two main causes are infection with Helicobacter pylori bacteria and long-term use of non-steroidal anti-inflammatory drugs (NSAIDs). Contrary to popular belief, stress and spicy food do not cause ulcers, though they can worsen symptoms.
H. pylori accounts for 70–90% of duodenal ulcers and ~70% of gastric ulcers in non-NSAID users. NSAIDs inhibit COX-1-mediated prostaglandin synthesis, reducing mucus secretion and mucosal blood flow. Diagnosis requires OGD with biopsy (CLO test / histology), urea breath test, or stool antigen test. Gastric ulcers mandate repeat OGD at 6–8 weeks to confirm healing and exclude malignancy.
Common Symptoms
- Burning or gnawing epigastric pain
- Pain relieved by eating (duodenal) or worsened by food (gastric)
- Nausea and bloating
- Loss of appetite and weight loss
- Dark or tarry stools (if bleeding)
Complications ⚠️
- Bleeding — most common; may require endoscopic haemostasis
- Perforation — surgical emergency; sudden severe abdominal pain
- Pyloric stenosis — scarring causing gastric outlet obstruction
- Malignant transformation — gastric ulcers require biopsy
Barrett's Oesophagus
Barrett's oesophagus is a condition where the normal squamous lining of the lower oesophagus is replaced by specialised columnar epithelium (intestinal metaplasia), as a result of chronic acid exposure from GERD. It is considered a pre-cancerous condition.
Most people with Barrett's oesophagus do not develop oesophageal cancer, but regular endoscopic surveillance is important to detect any progression to dysplasia (abnormal cells) at an early, treatable stage.
Barrett's is defined by ≥1 cm of columnar-lined oesophagus with confirmed intestinal metaplasia on biopsy (4-quadrant biopsies every 2 cm — Seattle protocol). Risk of progression to oesophageal adenocarcinoma: non-dysplastic ~0.3%/year; low-grade dysplasia ~0.5%/year; high-grade dysplasia ~7%/year. Endoscopic eradication therapy (RFA, cryotherapy, EMR, ESD) is indicated for confirmed dysplasia.
~10%
of chronic GERD patients develop Barrett's
5–10 yr
typical surveillance interval for non-dysplastic Barrett's
~95%
eradication success rate with radiofrequency ablation (RFA)
Oesophageal Strictures
An oesophageal stricture is a narrowing of the oesophagus that makes swallowing difficult or painful. Strictures can be benign (peptic, post-surgical, radiation-induced, eosinophilic oesophagitis) or malignant (oesophageal cancer).
The most common treatment is endoscopic balloon dilation or bougie dilation, which stretches the narrowed segment. Malignant strictures may require metal stent placement to maintain the lumen and allow the patient to eat.
Endoscopic Balloon Dilation — Clinical Considerations
Through-the-scope (TTS) balloon dilation uses controlled radial force to dilate oesophageal strictures under direct endoscopic vision. Balloon diameter is titrated based on stricture severity — the "rule of three" (no more than 3 mm increase per session) applies to bougie dilation. High-pressure through-the-scope balloons are particularly effective in tight peptic and anastomotic strictures. Success rates for benign strictures: ~80% at 1 year, though refractory strictures (requiring >5 dilation sessions) may need steroid injection, incision therapy (electrocautery / laser), or surgical resection. Radiation-induced strictures carry higher perforation risk and require particular care.
Benign Causes
- • Peptic stricture from chronic GERD
- • Post-surgical anastomotic narrowing
- • Radiation-induced fibrosis
- • Eosinophilic oesophagitis (EoE)
- • Chemical / caustic ingestion
- • Schatzki ring
Malignant Causes
- • Oesophageal squamous cell carcinoma
- • Oesophageal adenocarcinoma (Barrett's-related)
- • Gastric cardia tumour with proximal extension
- • Extrinsic compression (lung, mediastinal nodes)
Diagnosis & Endoscopy
Upper GI endoscopy (gastroscopy) is the definitive investigation. A thin, flexible tube with a camera on the end is passed through the mouth into the oesophagus, stomach, and duodenum. It allows the doctor to directly inspect the lining, take biopsies, and perform treatments — all in a single procedure.
Upper GI Endoscopy (OGD)
Direct visualisation, biopsy, and therapeutic access
H. pylori Testing
Urea breath test, stool antigen, CLO test, serology
Imaging & pH Studies
Barium swallow, CT, 24h pH-impedance, EUS
Endoscopic Interventions in Upper GI Disease
| Technique | Indication | Key Points |
|---|---|---|
| Balloon Dilation (TTS) | Benign strictures, anastomotic stenosis, achalasia (pneumatic) | Radial force; fluoroscopy guidance optional; high-pressure balloons for resistant strictures |
| EMR (Endoscopic Mucosal Resection) | Barrett's HGD, early cancer ≤20 mm | En-bloc preferred; inject-and-cut or cap technique |
| ESD (Endoscopic Submucosal Dissection) | Early oesophageal/gastric cancer >20 mm | En-bloc resection; technically demanding; risk of perforation |
| RFA (Radiofrequency Ablation) | Barrett's with dysplasia | HALO system; ~95% complete eradication |
| SEMS (Metal Stenting) | Malignant oesophageal obstruction | Palliative; restores swallowing; covered vs uncovered choice |
| Endoscopic Haemostasis | Bleeding peptic ulcer (Forrest Ia–IIb) | Dual therapy: adrenaline + thermal/clip; PPI infusion post-procedure |
上部GI治療：PPI、H. pylori除菌、バルーン拡張・内視鏡処置
Treatment depends on the specific condition, but most upper GI diseases respond well to a combination of lifestyle changes, medication, and when necessary, endoscopic or surgical procedures.
Lifestyle Modification
Elevate head of bed, lose weight, avoid trigger foods (caffeine, alcohol, fatty meals, citrus), stop smoking, eat smaller more frequent meals, avoid lying down within 3 hours of eating.
Acid Suppression Therapy
Proton pump inhibitors (PPIs — omeprazole, lansoprazole, pantoprazole) are the cornerstone of GERD and PUD treatment. H2-receptor antagonists (famotidine) are used as alternatives or add-on therapy. Antacids for symptomatic relief.
H. pylori Eradication
Standard triple therapy (PPI + clarithromycin + amoxicillin, 7–14 days) or bismuth-based quadruple therapy in areas with high clarithromycin resistance. Confirm eradication with urea breath test 4 weeks after completing treatment.
Endoscopic Intervention
Balloon dilation for strictures, haemostasis for bleeding ulcers, endoscopic mucosal resection (EMR) or radiofrequency ablation (RFA) for Barrett's with dysplasia, and stenting for malignant obstruction.
Surgery
Laparoscopic Nissen fundoplication for refractory GERD. Oesophagectomy or gastrectomy for cancers not amenable to endoscopic resection. Perforated or obstructed ulcers typically require emergency laparoscopic or open surgery.
Clinical Insights & Current Guidelines
BSG / ESGE 2023 Key Updates
- • Non-dysplastic Barrett's (<3 cm): surveillance OGD every 3–5 years; ≥3 cm every 2–3 years (BSG 2023).
- • Confirmed low-grade dysplasia: endoscopic eradication preferred over surveillance; RFA first-line.
- • ESGE recommends potassium-competitive acid blockers (P-CABs, e.g. vonoprazan) as an emerging alternative to PPIs in H. pylori eradication and erosive oesophagitis.
- • For suspected upper GI bleeding: OGD within 24h; <12h if haemodynamically unstable after resuscitation (ESGE 2021).
- • Risk stratification using Glasgow-Blatchford Score (GBS) pre-endoscopy; Rockall score post-endoscopy for re-bleeding risk.
Endoscope Hygiene & Single-Use Technology
Flexible endoscope reprocessing failures have been documented as vectors for H. pylori, multidrug-resistant organisms, and viral transmission. Single-use flexible endoscopes eliminate cross-contamination risk and maintain consistent optical performance — particularly relevant in immunocompromised patients and high-risk diagnostic procedures. Envaste's single-use scope portfolio aligns with the growing movement toward disposable endoscopy platforms in GI and pulmonology.
Balloon Dilation in Upper GI Strictures
Through-the-scope (TTS) balloon dilators — such as the Amara 3-Stage Balloon Dilator and the Amara Wire-Guided Balloon Dilator — are the standard of care for benign oesophageal, pyloric, and anastomotic strictures. Key technical principles: balloon placement under direct vision, fluoroscopic guidance for complex anatomy, and incremental dilation (no more than 3 Fr per session in fibrotic strictures). High-pressure balloons with radiopaque markers allow real-time waist obliteration confirmation. Intralesional corticosteroid injection at time of dilation reduces recurrence in refractory peptic strictures.
よくある質問：上部消化管疾患
GERD（胃食道逆流症）の症状は？
GERDは胸焼け（胸骨後部の灼熱感）、酸の逆流、嚥下困難（嚥下障害）、食後の胸部不快感を引き起こします。非典型症状には慢性咳嗽、嗄声、非心臓性胸痛が含まれます。GERDは症状が週2回以上発生する場合、または食道びらん、狭窄、バレット食道などの合併症を引き起こす場合に診断されます。
バレット食道とは何か、危険なのか？
バレット食道は、慢性的な胃酸逆流（GERD）による腸上皮化生によって下部食道の正常な粘膜が置換される状態です。前癌状態です。慢性GERD患者の約10%がバレット食道を発症します。定期的な内視鏡的サーベイランスにより異形成を早期発見し、高周波アブレーション（RFA）により異形成バレット食道の約95%の症例で根絶に成功します。
消化性潰瘍の原因と治療法は？
消化性潰瘍は、主にヘリコバクター・ピロリ（H. pylori）感染または長期的なNSAID使用による胃または十二指腸粘膜の潰瘍です。H. pyloriは十二指腸潰瘍の70〜90%の原因です。治療はプロトンポンプ阻害薬（PPI）療法と三剤または四剤抗菌薬療法によるH. pylori除菌を含みます。除菌は治療完了4週間後の尿素呼気試験で確認されます。
内視鏡的バルーン拡張術とは何か、いつ使用されるか？
内視鏡的バルーン拡張術は、スルー・ザ・スコープ（TTS）拡張バルーンを使用して食道、胃、または腸の狭窄部を拡張します。良性食道狭窄（GERD、術後、放射線誘発性）、幽門狭窄、吻合部狭窄を治療します。複雑な狭窄には透視誘導が使用されます。良性狭窄に対する1年間の成功率は約80%に達します。
胃内視鏡検査（上部GI内視鏡検査）とは何か、いつ必要か？
胃内視鏡検査（食道胃十二指腸内視鏡検査、OGD）は、口から細い軟性カメラを挿入して食道、胃、十二指腸を直接観察します。GERD、バレット食道、消化性潰瘍、H. pylori感染、食道狭窄、上部GI悪性腫瘍を診断します。また、バルーン拡張、出血性潰瘍の止血、悪性閉塞に対するステント留置などの治療的介入も可能にします。