What is the best approach to manage diarrhea in patients with scleroderma?

Management of Diarrhea in Scleroderma

For diarrhea in scleroderma patients, treat small intestinal bacterial overgrowth (SIBO) with rotating antibiotics as first-line therapy, use prokinetic agents for symptomatic motility disturbances, and maintain proton pump inhibitors (PPIs) for concurrent gastroesophageal reflux disease. 1

Pathophysiology Context

Scleroderma causes smooth muscle atrophy and gut wall fibrosis affecting the entire gastrointestinal tract, leading to hypomotility, bacterial overgrowth, malabsorption, and malnutrition. 1 The clinical outcome in elderly scleroderma patients with gastrointestinal involvement is particularly poor among all adult-onset dysmotility patients. 1

Primary Treatment Algorithm

Step 1: Evaluate for SIBO

• Diarrhea in scleroderma is most commonly caused by SIBO secondary to intestinal hypomotility. 2, 3
• Confirm SIBO with breath testing when available. 1
• Initiate intermittent or rotating antibiotics immediately for symptomatic SIBO. 1

Step 2: Add Prokinetic Therapy

• Use prokinetic drugs for symptomatic motility disturbances including diarrhea, bloating, early satiety, and pseudo-obstruction. 1
• Prucalopride (5-HT4 receptor agonist) has shown effectiveness in scleroderma patients, improving evacuation frequency and constipation scores. 1, 4
• Domperidone can be considered, though evidence shows modest benefit. 1
• Buspirone (5-HT1A receptor agonist) may help with lower esophageal sphincter dysfunction. 1

Step 3: Maintain PPI Therapy

• Continue PPIs for gastroesophageal reflux disease management, which affects 90% of scleroderma patients and can contribute to symptoms. 1
• PPIs prevent esophageal ulcers and strictures despite concerns about long-term use. 1

Specific Antibiotic Regimens

The EULAR guidelines recommend rotating antibiotics to prevent resistance, though specific regimens are not standardized. 1 Common approaches include:

• Rifaximin (non-absorbable, targets small bowel)
• Metronidazole (covers anaerobes)
• Ciprofloxacin or other fluoroquinolones
• Rotate every 1-2 weeks to prevent bacterial resistance 1

Nutritional Support Considerations

• For severe malabsorption and malnutrition despite medical therapy, long-term parenteral nutrition can be safe and effective. 1
• Elemental diets may help in advanced cases with severe hypomotility. 5
• Monitor for vitamin deficiencies, particularly fat-soluble vitamins due to malabsorption. 2

Critical Pitfalls to Avoid

Do not use antimotility agents like loperamide in scleroderma-related diarrhea. 6 These patients have underlying hypomotility, and further slowing transit worsens bacterial overgrowth and can precipitate pseudo-obstruction or even stercoral perforation. 5, 7

Monitor closely for complications:

• Pseudo-obstruction (may require nasogastric decompression and bowel rest) 5
• Pneumatosis cystoides intestinales (treat with oxygen therapy and bowel rest) 5
• Stercoral perforation from severe constipation alternating with diarrhea 7
• Fecal incontinence from anorectal involvement (affects quality of life significantly) 2

When Conservative Management Fails

• Consider octreotide for refractory diarrhea at 100-150 μg subcutaneously three times daily, escalating to 500 μg three times daily as needed. 8
• Surgical intervention (subtotal colectomy) may be necessary for severe colonic pseudo-obstruction unresponsive to medical therapy. 5
• Parenteral nutrition becomes essential when oral/enteral nutrition cannot maintain nutritional status. 1

Evidence Quality Note

The recommendations for antibiotics and prokinetics in scleroderma lack large randomized controlled trials but are supported by expert consensus from EULAR (the highest quality scleroderma guideline body) based on observational studies and clinical experience. 1 The 2025 EULAR update specifically retained these recommendations with strong patient representative advocacy given the substantial unmet need and real-world effectiveness. 1