Disease Description (Causes and Symptoms)
- Definition: Functional Gastrointestinal Disorder (FGID) refers to chronic gastrointestinal symptoms such as indigestion and abdominal discomfort that persist for more than 3 months even though no structural cause is identified on endoscopy or other tests. Representative forms include functional dyspepsia and irritable bowel syndrome.
- Main causes and pathophysiology (summary): There is no single known exact cause; it is multifactorial.
- Abnormal gastrointestinal motility (such as delayed gastric emptying)
- Visceral hypersensitivity
- Mild inflammation and immune responses in the gastrointestinal mucosa, and gut microbiota imbalance
- Excess stomach acid or Helicobacter pylori infection may be related in some patients
- Abnormalities in the gut–brain axis, and stress and emotional factors
- Medications (for example, some antibiotics, caffeine·carbonated beverages·alcohol, and certain cardiovascular medications) may trigger worsening symptoms
- Main symptoms:
- Upper abdominal discomfort and indigestion (postprandial fullness, early satiety, heartburn, belching, nausea)
- Abdominal bloating and gas
- Diarrhea or constipation (or alternating between them)
- Symptoms may worsen in relation to meals, and may fluctuate with stress, medications, or certain foods
Treatment Methods
- Treatment goals: Exclude structural causes, then relieve symptoms and improve quality of life
- Drug treatment (combined according to symptoms and causes)
- Gastrointestinal motility-improving drugs (for example, consider using probiotics/prokinetic agents) — be aware of the side effects of each medication (for example, long-term dementia-related dyskinesia with metoclopramide, etc.)
- Acid-suppressing drugs (PPI or H2 blocker) — used for heartburn and acid-related symptoms
- H. pylori eradication therapy when Helicobacter pylori is positive
- Antispasmodics, anticholinergics, and antispasmodic agents — used for abdominal pain and cramping symptoms
- Laxatives or antidiarrheal drugs according to constipation or diarrhea symptoms
- Low-dose antidepressants (tricyclic antidepressants, SSRIs, etc.) — used to improve pain and visceral hypersensitivity (psychiatric effects and side effects should be explained)
- Non-drug treatment
- Dietary and lifestyle improvements: eat regularly, eat slowly and chew thoroughly, avoid spicy foods, caffeine, carbonated beverages, alcohol, and smoking, and exercise appropriately
- Psychotherapy: cognitive behavioral therapy (CBT), stress management, and gut-directed hypnotherapy may help improve symptoms
- Gut microbiota modulation: probiotics or selective antibiotics (such as rifaximin) may help some patients (determined according to indications and evidence)
- Treatment duration and follow-up: Medications and treatment are individualized until symptoms improve. When using medications long term, side effects and effectiveness should be reassessed
- Precautions (during treatment)
- Explain potential side effects of specific medications in advance (for example, long-term dyskinesia from motility-improving drugs, drowsiness and dry mouth from low-dose antidepressants, etc.)
- If alarm symptoms (weight loss, hematemesis, melena, persistent vomiting, dysphagia, etc.) are present, immediate reassessment is necessary
- Exercise caution when selecting medications in cases of pregnancy, breastfeeding, or comorbidities (heart, liver, or kidney disease)
Checklist Before an Outpatient Visit (Including Preparation Items and Sample Questions)
- Preparation items and patient preparation
- List of currently used medications, supplements, and herbal medicines (a medication schedule if possible)
- Copies or summaries of previous test results (recent upper endoscopy, colonoscopy, abdominal ultrasonography, blood tests, etc.)
- Symptom diary: when symptoms occur, related factors (meals, stress, medications), times when symptoms are most severe, relationship to meals, and stool form and frequency (such as the Bristol Stool Scale)
- Records of weight changes
- Lifestyle information (smoking, alcohol use, sleep, and exercise)
- Examples of basic questions for the outpatient visit (prepare these in advance)
- When did the symptoms begin, and how have they progressed?
- How are the symptoms related to meals? Are they triggered by specific foods?
- Have you recently experienced any “warning symptoms (alarm symptoms),” such as weight changes, fatigue, fever, hematemesis, or melena?
- What medications or supplements are you currently taking?
Examples of General Questions to Ask the Doctor
- How can we determine with certainty whether these symptoms are functional gastrointestinal disorder? What additional tests are needed?
- What would be the recommended first treatment in my case? What are the expected effects and side effects of the medication?
- What is the most important lifestyle change I should make first?
- If my symptoms do not improve, what is the next step (additional tests, referral to a specialist, or psychotherapy)?
- What is the long-term prognosis?
Examples of Condition-Specific Questions
- (Suspected functional dyspepsia) My symptoms persist even though there were no abnormalities on endoscopy or blood tests. In what cases do you recommend Helicobacter pylori eradication therapy?
- (Bloating·diarrhea-type symptoms) Symptoms caused by certain foods (for example, dairy products, fructose, or FODMAPs) are suspected. May I try dietary restriction (a low-FODMAP diet)? How can I do this safely?
Additional Information
- Because functional gastrointestinal disorder itself is common and may recur chronically, ongoing communication with a doctor, maintaining a symptom diary, and improving lifestyle habits play important roles in treatment outcomes.
- If serious alarm symptoms (weight loss, persistent vomiting, hematemesis·melena, dysphagia, new severe pain, etc.) occur, emergency evaluation should be obtained.