irritable bowel syndrome

Gentle GI and NICE IBS Guidelines

What are the NICE Guidelines?

The NICE IBS Guidelines, also known as Gentle GI, are the strategies recommended as a first step by leading health organizations.

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Before moving on to any elimination diet, the National Institute for Health and Care Excellence (NICE)¹ and the British Dietetic Association (BDA)² recommend trying the following general modifications in diet and lifestyle (also named “traditional dietary advice”) based on reducing recognized IBS triggers.

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A recent study found that the traditional NICE IBS guidelines, the low FODMAP diet, and gluten-free diet all offered good symptom control in patients with non-constipated IBS.

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However, patients reported that the NICE guidelines were easier to follow when eating out, were cheaper, and required less time to shop.³

Here are the general principles of NICE guidelines:⁴

Have regular meals

Take time to eat

Avoid missing meals or leaving long gaps between meals

Drink at least 8 cups of fluid per day

Especially water or other non-caffeinated drinks (e.g., herbal teas)

Restrict tea and coffee to 3 cups a day

Reduce intake of alcohol and fizzy drinks

Reduce intake of foods rich in insoluble fiber

e.g., high-fiber flour and cereals, cereals high in bran, and whole grains such as brown rice

Reduce intake of resistant starch

found in processed or re-cooked foods

Limit fresh fruits to three servings per day

Diet Advice for Specific IBS Symptoms

Particular dietetic advice based on the predominant symptom is provided below:⁴

Symptom

Dietetic advice

Diarrhea

Avoid sorbitol-containing foods and products (e.g., sugar-free gum, sugar-free mints, stone fruits, and prunes).

Constipation

Incorporate two medium-sized green kiwifruits per day.
Try supplementation with flaxseed (2 tablespoons/day for 3 months)

Gas and bloating

Increase intake of oats and flaxseeds (up to 1 tablespoon per day)

A female doctor holding an ipad explaining something to a female patient

Personalized Support

Nutrition is a powerful tool, and when it is tailored to individual symptoms and lifestyle, it can become a sustainable part of managing IBS over the long term. Working with a GI dietitian can help personalize these principles and support confident, informed decision-making.

Find out more about other evidence-based dietary therapies for IBS to discuss with your dietitian.

Explore more dietary options

References

Hookway C, Buckner S, Crosland P, et al. Irritable bowel syndrome in adults in primary care: summary of updated NICE guidance. BMJ. 2015; 350:h701. doi: 10.1136/bmj.h701.
McKenzie YA, Bowyer RK, Leach H, et al. 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; 29(5):549-75. doi: 10.1111/jhn.12385.
Rej A, Sanders DS, Shaw CC, et al. Efficacy and acceptability of dietary therapies in non-constipated irritable bowel syndrome: a randomized trial of traditional dietary advice, the low FODMAP diet, and the gluten-free diet. Clin Gastroenterol Hepatol. 2022; 20(12):2876-2887.e15. doi: 10.1016/j.cgh.2022.02.045.
Singh P, Tuck C, Gibson PR, et al. The role of food in the treatment of bowel disorders: focus on irritable bowel syndrome and functional constipation. Am J Gastroenterol. 2022; 117(6):947-957. doi: 10.14309/ajg.0000000000001767.