Information for Referring Clinicians
I am an HCPC-registered (No. DT06322) Specialist Gastroenterology Dietitian with professional indemnity through the British Dietetics Association.
I am currently leading a working group for the 2026 revision of the British Dietetic Association’s national IBS guidelines, authoring a new section on non-dietary considerations, differential diagnosis, and signposting — the first time the guidelines have addressed this area. I previously co-authored the 2016 BDA IBS guidelines (McKenzie YA et al., J Hum Nutr Diet 2016) and founded the first NHS Dietetic-Led Primary Care Gastroenterology Clinic in the UK — the published outcomes from which are summarised below. I take referrals from gastroenterology, surgical, and primary care teams across the UK.
To refer: Email me directly at marianne@wisediet.co.uk with the patient’s details or a brief referral letter. No referral form is required.
Turnaround: Patients referred by a medical professional are normally seen within 1–2 weeks.
What you receive: The patient receives a full personalised dietetic report. A clinic letter back to your team is provided on patient agreement, summarising the assessment, dietary recommendations, and ongoing plan.
Patient consultation fees
Initial dietetic consultation Includes pre-assessment of medical & diet history, 1 hour consultation, full personalised report, and letter to referring team on approval: £130
Dietetic review 30 minutes, includes updated report and letter: £80
Patients pre-pay directly. Patients are welcome to invoice their insurers. I do not invoice insurers.
I see adult patients (18+) with:
Irritable bowel syndrome, including refractory IBS where first-line dietary advice has not been sufficient
IBS-overlap symptoms in patients with quiescent inflammatory bowel disease
Coeliac disease, non-coeliac gluten sensitivity, and wheat allergy — including the diagnostic distinction from IBS-type fermentation symptoms
Diverticular disease
Food allergy affecting the gut, including non-IgE mediated reactions where conventional allergy tests are unhelpful
Eosinophilic oesophagitis — dietary elimination and nutritional support
Pollen Food Syndrome
Histamine sensitivity / vasoactive amine intolerance
Post-COVID IBS
Ehlers-Danlos Syndrome with gastrointestinal symptoms
Bile salt malabsorption
Small intestinal bacterial overgrowth (SIBO)
Stoma management, including use of the low FODMAP diet to reduce stoma overflow
Conditions outside my scope:
Adults only. I do not see paediatric patients (under 18).
Primary eating disorders. Where the eating disorder is the primary diagnosis, the patient is best supported by an eating disorders service.
Severe acute IBD flare. Patients requiring in-hospital management are best supported by their hospital dietetic team.
New resection/bowel surgery. Patients requiring in-hospital management are best supported by their hospital dietetic team.
Home parenteral nutrition and intestinal failure. I do not manage TPN-dependent intestinal failure cases.
If you’re unsure whether a patient falls within scope, please email me — I’m happy to confirm before you refer.
How a referral works
1. Email me at marianne@wisediet.co.uk with the patient’s name and contact details and your referral letter.
2. I contact the patient directly to schedule. Patients referred by a clinician are normally seen within 1–2 weeks.
3. The patient completes a pre-assessment case-history and diet-history questionnaire before the first appointment.
4. Consultations are conducted via Zoom — no travel required. The initial appointment is one hour; review appointments are 30 minutes.
5. The patient receives a full personalised dietetic report after the initial consultation.
6. With the patients permission I send a clinic letter back to your team summarising the assessment, dietary recommendations, and ongoing plan.
“63% of patients achieved satisfactory IBS control; 74% reported improved quality of life following dietetic intervention in the NHS Dietetic-Led Primary Care Gastroenterology Clinic I founded in Somerset”
— Williams M et al., Frontline Gastroenterology, 2016“Symptom improvements are sustained long-term. In a follow-up service evaluation at a median of 13 months post-intervention (n=211), the proportion of patients reporting satisfactory symptom relief rose from 10% at baseline to 55% (p<0.001)”
— Seamark L, Williams M et al., J Hum Nutr Diet, 2021“Dietetic intervention reduces downstream healthcare contact. In the same cohort, the proportion of patients consulting their GP about IBS symptoms in the year following dietetic input fell from 96% to 34% (p<0.001), and gastroenterologist consultations fell from 37% to 12% (p=0.002).”
— Seamark L, Williams M et al., J Hum Nutr Diet, 2021“The pathway was cost-effective for the NHS. The Somerset pathway reduced overall costs by 25% for patients aged 16–45 with likely IBS and no alarm symptoms, delivering estimated annual savings of approximately £102,000 in the pilot region”
— Williams M et al., Frontline Gastroenterology, 2016Selected publications
Hyperlinks below go to each paper.
• BDA national IBS guidelines (2026 revision, in development). Lead author of a new section on non-dietary considerations, differential diagnosis, and signposting — the first time this area has been included in the BDA IBS guidelines. British Dietetic Association, due 2026.
• McKenzie YA, Bowyer RK, Leach H, Gulia P, Horobin J, O’Sullivan NA, Pettitt C, Reeves LB, Seamark L, Williams M, Thompson J, Lomer MCE. British Dietetic Association systematic review and evidence-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update). J Hum Nutr Diet, 2016. doi:10.1111/jhn.12385
• Williams M, Barclay Y, Benneyworth R, et al. Using best practice to create a pathway to improve management of irritable bowel syndrome: aiming for timely diagnosis, effective treatment and equitable care. Frontline Gastroenterology, 2016. doi:10.1136/flgastro-2016-100727
• Seamark L, Barclay Y, Marchant C, Williams M, Hickson M. Long-term symptom severity in people with irritable bowel syndrome following dietetic treatment in primary care: a service evaluation. J Hum Nutr Diet, 2021. doi:10.1111/jhn.12860
• Williams M, Barclay Y, Harper L, Marchant C, Seamark L, Hickson M. Feasibility, acceptability and cost efficiency of using webinars to deliver first-line patient education for people with Irritable Bowel Syndrome. J Hum Nutr Diet, 2020;33:758–766. doi:10.1111/jhn.12799
• Colgan A, Digby K, Apekey T, Elborough-Whitehouse I, Seamark L, Radcliffe O, Williams M, Hickson M. A dietitian-led low-FODMAP diet webinar: a pre-post study evaluating its impact on symptoms of irritable bowel syndrome. J Hum Nutr Diet, 2023. doi:10.1111/jhn.13262