How should I manage a patient diagnosed with SIBO who is experiencing recurrent symptoms after treatment?

For a patient experiencing recurrent symptoms after treatment for small intestinal bacterial overgrowth (SIBO), management in UK General Practice primarily aligns with the approach for Irritable Bowel Syndrome (IBS), as UK guidelines do not typically recommend hydrogen breath tests for bacterial overgrowth to confirm an IBS diagnosis ². While international guidelines, such as those from the Brazilian Federation of Gastroenterology, provide specific guidance on the diagnosis and treatment of SIBO ((Silva et al., 2025)), the UK approach focuses on symptom management.

Key management steps for recurrent symptoms include:

• Explanation and Reassurance: Explain that conditions like IBS are chronic with fluctuating symptoms, often triggered by stress, illness, or diet ¹. Reassure the patient that the aim is to improve symptoms and quality of life, as complete relief may not be achievable ¹.
• Dietary and Lifestyle Advice:
  • Advise the patient to eat regular, healthy, balanced meals and ensure adequate fluid intake (at least 8 cups per day, mainly water or non-caffeinated drinks) ¹,².
  • Suggest adjusting fibre intake based on predominant symptoms; soluble fibre (e.g., oats, linseeds, ispaghula) may be beneficial, while insoluble fibre (e.g., bran, wholemeal flour) should be reduced ¹,².
  • Recommend limiting intake of caffeine, alcohol, carbonated drinks, and gas-producing foods ¹,². Also, advise reducing 'resistant starch' found in processed or re-cooked foods and limiting fresh fruit to three portions per day ².
  • Encourage regular physical activity (e.g., 30 minutes of moderate intensity on at least 5 days a week) ¹.
  • Discuss mental wellbeing, encouraging the patient to identify and manage stress, anxiety, or depression ¹.
  • If the patient chooses to try probiotic supplements, advise them to take the product for at least 4 to 12 weeks and discontinue if there is no improvement ¹,².
• Further Dietary Management and Referral: If symptoms persist despite general lifestyle and dietary advice, consider referring the patient to a specialist dietitian ¹,². A dietitian can provide expert advice on single food avoidance or exclusion diets, such as a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet, ensuring nutritional balance and avoiding deficiencies ¹,².
• Pharmacological Symptom Management: Depending on predominant symptoms, consider pharmacological treatments such as antispasmodics, laxatives (avoiding lactulose), or loperamide ². Tricyclic antidepressants (TCAs) may be considered as a second-line treatment if other options are ineffective ².
• Psychological Interventions: For refractory symptoms that do not respond to pharmacological treatments after 12 months, consider referral for psychological interventions like cognitive behavioural therapy (CBT) or hypnotherapy ².
• Follow-up: Arrange to review the patient within two months of diagnosis to assess symptom progression and treatment efficacy ¹. Subsequent follow-up should be agreed upon based on symptom response, typically as part of an annual patient review ². Always be vigilant for 'red flag' symptoms that would prompt further investigation or referral to secondary care ².