The Resilient Gut System™ — The Map · The Investigation · The Case

Does this sound familiar?

Your gut feels like it has
a mind of its own

Symptoms come and go without explanation. What worked yesterday doesn't work today. You've been careful, restricted, and diligent — and you're still not fully better.

◦Your digestion feels unpredictable — good days and bad days with no clear pattern

◦Symptoms consistently worsen during stressful periods at work or at home

◦You've tried elimination diets, low-FODMAP, and cutting foods — nothing has fully stuck

◦You're unsure which foods are actually safe and which are the real triggers

◦You're managing this alongside a busy, demanding life with limited headspace

◦You want a clear, structured approach — not another list of things to try

The problem most people miss

Digestive symptoms are not just about food

They are strongly influenced by stress, nervous system regulation, circadian rhythm, and daily lifestyle patterns. The gut and the brain are in constant two-way communication via the vagus nerve. When that connection is dysregulated — through chronic stress, poor sleep, or HPA axis exhaustion — digestion suffers regardless of how carefully you eat.

That's why restrictive diets so often fail. They address what you eat. They don't address why your gut is reacting the way it is.

"The upstream driver of most digestive dysfunction is the state of the nervous system — and that changes everything about how the gut should be approached."

The Resilient Gut System™ begins where most programmes stop: with the nervous system, the stress-gut connection, and the conditions under which the gut can actually heal. Testing is added where it provides genuine clinical direction — not as a default, but as a targeted investigation when the case demands it.

The Programme Framework

Five phases. Built from clinical practice.

The Resilient Gut System™ follows a step-by-step framework used in clinical practice across 37 years. Each phase builds on the last — beginning with nervous system regulation and working progressively toward long-term resilience and food confidence.

Calm the System First

Before addressing food, we address the nervous system. Stress-driven gut reactivity cannot be resolved by dietary manipulation alone. This phase establishes the parasympathetic foundation that makes everything else possible — breathwork, circadian alignment, HPA load reduction, movement calibration.

Eat in a Way Your Gut Can Trust

Not another elimination protocol. This phase rebuilds food confidence through structured, evidence-based approaches to eating patterns, macronutrient balance, meal timing, and the foods that support rather than burden your gut. The goal is trust, not restriction.

Support the Gut — Without Overdoing It

Targeted, minimal support based on your specific presentation. Not a supplement stack applied without clinical rationale. Digestive support, gut-microbiome nutrition, and key cofactors — precisely where your system needs them. Tier 2 and 3 clients receive GI-MAP test-guided support at this phase.

Move, Recover and Release Stress

Movement that builds energy rather than depletes it. For a stressed gut, high-intensity exercise is often counterproductive. This phase introduces zone-appropriate movement — breathwork, qi gong, restorative movement — matched to where your nervous system actually is, not where you want it to be.

Sustain, Adapt and Future-Proof

The final phase builds the toolkit for long-term resilience. Understanding your patterns, reading early warning signs, adjusting around life's inevitable stressors, and maintaining what you've built when circumstances change. This is where results become permanent rather than temporary.

Three Levels of Support

The Map. The Investigation.
The Case.

The programme framework is the same across all three tiers. What changes is the depth of clinical investigation, the level of practitioner oversight, and the number of strategy sessions built in. Every tier carries full upgrade credit — whatever you invest now applies in full if you move up.

Tier One · The Map

The Map

Orientation. Structure. The full framework.

£697

One-time · Full programme access

What's included

8 guided modules — all five phases
Practice Better portal access
Video lessons + written content
Implementation guides for each phase
Supplement protocol framework
Food and lifestyle tools
Metabolic Nature nutrition module
Lifetime access to all materials

Enrol Now →

Upgrade to The Investigation at any time — £697 applied in full

Order your GI-MAP kit

Once your programme payment is confirmed, complete the form below to arrange dispatch of your GI-MAP test kit. The kit is sent directly to your address — a simple stool sample is collected at home and returned to the laboratory in the prepaid envelope provided. Results are typically returned within 10–14 days. Stephen will review your results and prepare a written interpretation ahead of your strategy consultation.

Complete form below

Kit dispatched to your address

Sample collected at home, returned by post

Results reviewed in your strategy session

Tier 3 Option · GI-MAP + OAT Upgrade

For complex or resistant cases — add the Organic Acids Test

The OAT (Organic Acids Test) adds mitochondrial function, neurotransmitter metabolites, Krebs cycle efficiency, and nutrient cofactor status to the gut picture. For clients with chronic, multi-system, or treatment-resistant presentations — where gut symptoms intersect with fatigue, mood, cognitive function, or poor treatment response — the GI-MAP + OAT combination provides a significantly more complete clinical picture. Tier 3 clients can add the OAT at a discounted combined rate of £895 (GI-MAP + OAT). Select this option in the form below.

Test Kit Order Form · Tier 2 and Tier 3 Clients Only

Personal Details

First name *

Last name *

Email address *

Phone number *

Date of birth *

Programme tier *

Delivery Address for Test Kit

Address line 1 *

Address line 2

Town / City *

Postcode *

Country *

Additional Information

Anything useful to know before the kit is dispatched?

This form is for test kit dispatch only. Payment is taken separately via the Stripe link above. Your details are used solely to arrange kit dispatch via Nordic Laboratories and will not be shared with any third party. You will receive an email confirmation once your order has been placed.

✓ Order received. You'll receive a confirmation email within 24 hours, and your kit will be dispatched within 2–3 working days. If you have any questions in the meantime, email stephen@detective-health.com

Your Practitioner

BSc (Hons) Developmental Biology
PG Dip Health Informatics
MSc Coaching & Applied Physiology
FDN-P · Metabolic Typing Advisor L2
37 Years Clinical Experience
Edinburgh

Clinical rigour.
Human practice.

Stephen Duncan is a Functional Diagnostic Nutrition Practitioner (FDN-P) with a background in developmental biology, health informatics, and applied physiology. He has 37 years of experience spanning athletics coaching, boxing, and over two decades of functional medicine clinical practice in Edinburgh.

The Resilient Gut System™ was built from real clinical experience with clients navigating IBS, stress-driven gut dysfunction, and the frustration of approaches that address symptoms without addressing cause. The programme reflects what actually works — a structured, honest, stress-first approach to digestive health.

For clients requiring comprehensive functional testing — blood chemistry, GI-MAP, DUTCH hormone panel, and organic acids — the full TDG Five-Test Programme is available as the next step, with full RGS investment applied as credit.

Your gut feels like it hasa mind of its own