What is the recommended workup for abdominal bloating?

Recommended Workup for Abdominal Bloating

The initial workup for abdominal bloating should focus on ruling out common causes through targeted testing, with abdominal imaging and endoscopy reserved only for patients with alarm features or abnormal physical examination findings. 1

Initial Diagnostic Approach

History and Physical Examination Focus

• Assess for Rome IV criteria to diagnose primary abdominal bloating and distention
• Evaluate for alarm features:
  • Weight loss
  • Blood in stool
  • Age >50 years (especially women, due to ovarian cancer risk)
  • Recent worsening of symptoms
  • Family history of colorectal cancer or inflammatory bowel disease

First-Line Testing

1. Carbohydrate malabsorption evaluation:

   • Dietary restriction trials and/or breath testing for lactose, fructose, and sorbitol intolerance 1, 2
   • Consider glucose- or lactulose-based hydrogen breath testing for small intestinal bacterial overgrowth (SIBO) in high-risk patients only 1

2. Celiac disease screening:

   • Tissue transglutaminase IgA and total IgA levels 1
   • If positive serology, proceed to small bowel biopsy for confirmation

3. Basic laboratory tests:

   • Complete blood count (to assess for anemia)
   • Comprehensive metabolic panel
   • Fecal elastase (if chronic pancreatitis suspected) 1

Second-Line Testing (Based on Specific Symptoms)

For Patients with Constipation or Difficult Evacuation

• Abdominal X-ray to assess stool burden 1
• Anorectal physiology testing (anorectal manometry with balloon expulsion) to evaluate for pelvic floor disorders 1
• Consider defecography (barium or MRI) if structural etiology suspected 1

For Patients with Nausea and Vomiting

• Gastric emptying study (not recommended for bloating alone) 1
• Consider upper endoscopy in patients >40 years with dyspeptic symptoms, especially in areas with high H. pylori prevalence 1

For Patients with Alarm Features

• Abdominal imaging (CT or ultrasound) 1
• Upper endoscopy 1
• Colonoscopy (if lower GI symptoms or alarm features present)

Important Clinical Considerations

When to Avoid Unnecessary Testing

• Do not routinely order:
  • Gastric emptying studies for bloating without nausea/vomiting 1
  • Whole gut motility studies unless refractory lower GI symptoms exist 1
  • Abdominal imaging without alarm features 1

Common Pitfalls to Avoid

1. Overlooking pelvic floor disorders in patients with constipation and bloating
2. Failing to screen for celiac disease in patients with chronic bloating
3. Overuse of imaging studies in patients without alarm features
4. Missing ovarian cancer in women >50 years with new-onset bloating
5. Attributing symptoms to gastroparesis without appropriate testing

Treatment Considerations

• Linaclotide may be effective for bloating in IBS-C patients, with 34% of patients showing improvement in abdominal symptoms compared to 14-21% with placebo 3
• Dietary interventions, particularly for those with carbohydrate malabsorption, can provide long-term relief in up to 67% of patients 2
• Avoid recommending probiotics for bloating treatment 1

By following this systematic approach to the workup of abdominal bloating, clinicians can identify the underlying cause while avoiding unnecessary testing, leading to more effective management and improved quality of life for patients.