II. Definitions
- Functional Gastrointestinal Disorders (FGID)
- Bloating
- Sensation of gasseousness or distention (with or without abdominal girth changes)
- Belching (Eructation, Burping)
- Flatulence (Farting, Abdominal Wind)
- Excessive colonic gas expulsion from the anus
III. Pathophysiology
- Belching: Gas in Stomach from air Swallowing (Aerophagia)
- Hurried Eating or Drinking
- Smoking or Chewing gum
- Wearing badly fitted dentures
- Postnasal drainage
- Dry Mouth from anxiety or Anticholinergics
- Bloating and Abdominal Distention
- Altered intestinal motility and transit typically of the Small Intestine
- CNS processing (lower pain threshold)
- Visceral Hypersensitivity
- Other factors such as gut microflora and immune function may play a role
- Typically not related to increased gas production
- Not typically related to Flatulence (gas in colon does not cause bloating Sensation in most cases)
- Not typically related to Belching (due to swallowed air, not gas generated in Small Intestine)
- Flatulence: Gas from Large Intestine
- Typically diet related
- Bacterial degradation of Large Intestine contents
- Indigestible Carbohydrates
- Malabsorption (e.g. Lactose Intolerance)
IV. Symptoms
- Eructation
- Bloating
- Borborygmus
- Flatulence
V. History
-
General
- Symptoms and their timing
- Palliative and provocative measures
- Recent illness
- Emotional stress
- Abdominal surgeries
- Gastrointestinal and genitourinary disorders
- Able to eat a full plate of food?
- Regular, normal Bowel Movements?
- Dietary history
- Meal patterns (e.g. large meals, rapid eating)
- Caffeine
- Carbonated drinks
- FODMAPs (Fementable Oligosaccharides, Disaccharides, Monosaccharides and Polyols)
- See FODMAP
- Fructose (e.g. apples, pears, peaches, mangoes, dried fruit, honey, fruit juice, high fructose corn syrup)
- Fructans (fructo-Oligosaccharides, inulins, levans - e.g. high fiber bars, onions, leeks, zucchini)
- Disaccharides (Lactose): Dairy, cheese, milk
- Polyols: Apricots, peaches
- Galactooligosaccharides or Raffinose (brussel sprouts, cabbage, green beans, lentils, legumes, chick peas)
- Medications
VI. Exam
- General examination
- Focused abdominal exam
- Rectal Exam
VII. Findings: Red Flag Symptoms and signs
- Unintentional Weight Loss
- Fever
- Vomiting
- Gastrointestinal Bleeding
- Abdominal mass
- Dysphagia
- Jaundice
- Lymphadenopathy
- Severe symptoms
- Severe Diarrhea
- Tenesmus
- New onset in over age 55 years
- Cancer history
VIII. Associated Conditions
- Emotion and Stress exacerbate symptoms (but are not typically the underlying cause)
- Anxiety
- Depressed mood
- Emotional stress
- Comorbid illness
IX. Differential Diagnosis
- Bloating or Abdominal Distention in general
- Abdominal Mass
- Pregnancy
- Abdominal Wall Hernia (e.g. Umbilical Hernia, Ventral Hernia)
- Ovarian Cancer
- Ascites
- Eructation (Belching, Burping)
- Typically aerophagia (see pathophysiology above)
- Gastric Belching
- Hurried Eating or Drinking
- Smoking or Chewing gum
- Wearing badly fitted dentures
- Postnasal drainage
- Xerostomia
- Gastroesophageal Reflux Disease
- Functional Dyspepsia
- Supragastric Belching
- Gastric Bloating (symptoms begin <30 minutes after eating)
- See Dyspepsia Causes
- Functional Dyspepsia
- Post-prandial fullness, early satiety and bloating
- Epigastric Pain not related to eating may also occur
- Gastroesophageal Reflux Disease
- Helicobacter Pylori infection
- Gastroparesis (post-Viral Gastroenteritis, Diabetes Mellitus, Bariatric Surgery)
- Impaired gastric accommodation
- Gastric outlet obstruction (esp. chronic Peptic Ulcer Disease with scarring)
- Delayed Gastric Emptying
-
Small Bowel Bloating (symptoms begin >30 minutes after eating)
- Pain-Dominant Irritable Bowel Syndrome
- Celiac Sprue (Gluten Sensitive Enteropathy)
- Dietary intake (see FODMAPs listed above)
- Bacterial overgrowth within Small Intestine
-
Constipation with Bloating
- See Constipation Causes
- See Medication Causes of Constipation
- Chronic Constipation (Functional Constipation)
- Constipation-Dominant Irritable Bowel Syndrome
- Slow transit Constipation
- Dyssynergic Defecation (Pelvic Floor Dysfunction)
- Lack of coordination between abdominal wall, pelvic floor and anal sphincter on attempted Defecation
- Treated with pelvic floor retraining
X. Evaluation: Testing to consider
- Eructation (Belching, Burping)
- No testing is typically needed, as this is nearly always aerophagia
- Gastric Bloating (symptoms begin <30 minutes after eating)
- Upper endoscopy
- Hemoglobin A1C
- Gastric Emptying Study
-
Small Bowel Bloating (symptoms begin >30 minutes after eating)
- Celiac Sprue: IgA Tissue Transglutaminase (TTG) and Total IgA (if low, obtain IgG Gliadin instead of TTG)
- Hydrogen Breath Test
- Bloating with Constipation
- Rectal Exam (impaction, Pelvic Floor Dysfunction)
- Thyroid Stimulating Hormone (TSH)
- Serum Calcium
- Colonoscopy
- Colon transit study
- Anorectal manometry
XI. Management
-
General
- Avoid discounting patient concerns (as with other functional disorders)
- Offer reassurance when findings are consistent with functional gastrointestinal disorder
- Manage underlying emotional stress and Mood Disorders (Major Depression, Anxiety Disorder)
- Consider Exercise (esp. Irritable Bowel Syndrome, Chronic Constipation)
- Exclude secondary causes
- Perform testing as indicated based on history including red flag symptoms
- Consider medication and dietary causes
- Eliminate causative factors
- Manage aerophagia in Eructation
- Reduce FODMAPs in bloating
- Follow specific management strategies for Functional Gastrointestinal Disorders
- Consider empiric management for common conditions
- Consider Proton Pump Inhibitor for Functional Dyspepsia
- Consider antispasmodics (e.g. Hyoscyamine, Dicyclomine, Peppermint Oil) for Irritable Bowel Syndrome
- Consider fiber supplementation in Irritable Bowel Syndrome, Chronic Constipation (after initial disimpaction regimen)
- Avoid measures without evidence
- Simethicone
- No evidence that Simethicone is better than Placebo
- Simethicone