Food and digestion
Food intolerances in St. Gallen
Laboratory analysis. Personal guidance.
Would you like personal support with questions about food and digestion? At Klosterdrogerie, we offer IgG4 analysis through Ortho-Analytic, breath tests and a detailed discussion of your laboratory report. We take time for your questions and explain the findings in the context of your symptoms.
Start with the right question
Food intolerance or food allergy?
Food intolerance
An intolerance can involve difficulty digesting or absorbing a food component, as with lactose. Bloating, abdominal pain and diarrhoea may occur. These symptoms can also have other causes, so recurring discomfort needs appropriate assessment.
Food allergy
A food allergy involves the immune system and requires a different diagnostic approach. Reactions can affect the skin, digestion, breathing or circulation. Suspected food allergies should be assessed by a doctor or allergy specialist.
Sudden breathing difficulties, swelling of the mouth or throat, or collapse after eating may be an emergency. Call 144 in Switzerland for urgent medical help.
Our services
Analysis and personal report discussion
From the first enquiry to your report discussion, we explain the available tests, help you with the arrangements and take time for your questions.
IgG4 blood analysis by Ortho-Analytic
The analysis measures food-specific IgG4 antibodies in venous blood. Blood sampling takes place at a laboratory partner or, on request, at your own GP practice. Once the results are available, we arrange an appointment to discuss your report with you at Klosterdrogerie.
In our advisory practice, we have had positive experiences with the combination of testing and individually adjusted diets. We draw on these experiences when discussing your results and advising you on possible dietary adjustments. Individual responses can vary.
Your report provides measurements of food-specific IgG4 antibodies. We discuss them alongside your symptoms and previous investigations. An increased IgG4 value alone does not establish a food intolerance; the clinical usefulness of IgG4-guided dietary changes is still being researched.
Breath tests: lactose, fructose and sorbitol
We also offer breath tests for questions about lactose, fructose and sorbitol. These tests measure gases in exhaled air and are interpreted together with the symptoms recorded during testing.
Before your appointment, we explain the preparation and procedure for the selected test. During your report discussion, we put the findings in context and discuss any further clarification that may be needed.
From enquiry to discussion
How to get started
1. Get in touch
Tell us about your questions and any previous investigations. We explain the available services and clarify the appointment arrangements with you.
2. Arrange sampling or testing
For the IgG4 analysis, the venous blood sample is collected at a laboratory partner or, on request, at your own GP practice. Contact us first to clarify the arrangements. For a breath test, follow the specific preparation instructions.
3. Discuss the results
Your personal report discussion gives you time to understand the measurements and ask questions. Together, we consider the findings alongside your symptoms, medical history and previous investigations.
A venous blood sample is taken at a laboratory partner or, on request, at your own GP practice. Klosterdrogerie does not perform the blood collection. Please contact us beforehand to clarify the arrangements and sampling requirements.
Some studies have reported improvements in symptoms with antibody-guided exclusion diets in selected groups of people with irritable bowel syndrome or Crohn's disease. This includes studies using IgG4 measurements. A larger trial published in 2025 used a specialised IgG test, which differs from the Ortho-Analytic IgG4 analysis. The findings cannot automatically be transferred between tests or patient groups. Research is continuing, and these results do not validate IgG4 testing as a general diagnostic test for food intolerances.
Read the original studies:
Preparation depends on the test. Contact us for the specific instructions before your appointment. Do not change or stop prescribed medicines on your own; clarify any questions with the prescribing doctor.
We discuss the measurements in the context of your symptoms and eating habits. An IgG4 report alone does not identify which foods you need to avoid. Our team provides personal advice and individual recommendations on possible dietary adjustments, taking your symptoms, eating habits and balanced nutrition into account. If you have a pre-existing condition, dietary changes should be coordinated with your treating doctor.