Motility, IBS & the brain-gut axis
One of 5 mechanistic pathways to 🦠 Gut health & digestion · 14 options
The gut has its own nervous system with more neurons than the spinal cord, and it talks to the brain continuously. IBS is a disorder of that communication as much as of the gut itself — which is why psychological interventions genuinely outperform most drugs in trials.
Thyroid sets gut transit speed — hypothyroidism causes constipation, hyperthyroidism causes the opposite — and it is the most common organic cause hiding behind an IBS label.
TSH (Thyroid-Stimulating Hormone)Free T3 (Triiodothyronine)Complete Blood Count (CBC) with Differentialhs-CRP (High-Sensitivity C-Reactive Protein)Ferritin🌱 Gut Health & Absorption covers these in one panel →
What engages this pathway
Ordered by how directly each one acts on the mechanism above — never by how much trial evidence exists. Each links to its full breakdown with dosing, half-life and vendor.
🧬 Peppermint Oil
Enteric-coated so it reaches the small intestine, where menthol blocks calcium channels in smooth muscle. Meta-analyses put it among the most effective IBS treatments available, prescription included.
🧬 Partially Hydrolysed Guar Gum (PHGG)
Improves both constipation- and diarrhoea-predominant IBS in trials without the fermentation load of other fibres.
🧬 Psyllium Husk
Normalises stool form in both directions — one of very few things with that property.
🧬 Probiotic
Specific strains reduce IBS symptom severity; strain selection is the entire question.
🧬 L-Theanine
Reduces the sympathetic tone that drives gut hypersensitivity.
🧬 Magnesium
Osmotic laxative effect in the citrate and oxide forms; muscle-relaxant contribution in all forms.
🧬 Triphala
Traditional Ayurvedic bowel regulator with trial evidence for constipation, and it does not cause the dependence senna does.
🧬 Senna
A stimulant laxative acting on the myenteric plexus. Effective and habit-forming with chronic use — for rescue, not for management.
🧬 Bismuth Subsalicylate
Antisecretory and antimicrobial. Also used in H. pylori quadruple therapy.
🧬 Activated Charcoal
Adsorbs gas and toxins non-selectively — including your medications, which is the interaction people forget.
💉 Ondansetron
5-HT3 antagonism slows transit and has real randomised evidence in diarrhoea-predominant IBS.
💉 Low Dose Naltrexone
Small trials in Crohn's show mucosal healing; the microglial and enteric anti-inflammatory argument.
🧬 Chamomile (Apigenin-standardised)
Antispasmodic and anxiolytic — both ends of the axis at once.
🧬 Lemon Balm
Traditional carminative with modern anxiolytic data.
The other 4 routes to gut health & digestion
Pick the pathway that matches where you are actually stuck. An appetite drug does nothing for someone who already undereats.
Want the protocols behind these?
Dosing schedules, stacking, cycle timing and Coach Cam's notes live inside the Academy — plus the full interactive Vault.
Join the Academy — $10/mo →← Open this pathway in the interactive Vault
Frequently asked questions
The gut has its own nervous system with more neurons than the spinal cord, and it talks to the brain continuously. IBS is a disorder of that communication as much as of the gut itself — which is why psychological interventions genuinely outperform most drugs in trials.
14 options are mapped to this pathway in the Vault, including Peppermint Oil, Partially Hydrolysed Guar Gum (PHGG), Psyllium Husk, Probiotic. They are grouped by the mechanism they act through rather than ranked by how much trial evidence exists — 12 carry clinical validation and 2 are mechanistic predictions.
Thyroid sets gut transit speed — hypothyroidism causes constipation, hyperthyroidism causes the opposite — and it is the most common organic cause hiding behind an IBS label. The markers worth checking are TSH (Thyroid-Stimulating Hormone), Free T3 (Triiodothyronine), Complete Blood Count (CBC) with Differential, hs-CRP (High-Sensitivity C-Reactive Protein).
Unproven is not the same as ineffective. Of the 14 options on this pathway, 12 have clinical validation and 2 are graded theoretical — meaning the mechanism is sound but the specific human trial has not been run, which is true of a great deal of what works in this space. Nothing on this page is ordered by evidence tier, because sorting by trial count would bury the compounds you came looking for.