What is a SIBO Specific Carbohydrate Diet (SCD)?

What is SIBO?

In short SIBO stands for Small Intestine Bacterial Overgrowth. It’s a gastrointestinal disorder that occurs when there are excessive bacteria in the small intestine. For more details and a list of symptoms please read my post “SIBO – A Basic Guide”.

A SIBO Specific Carbohydrate Diet is a combination of a SCD diet and a low FODMAP diet.

A Specific Carbohydrate Diet or SCD for short, is a way of eating developed by the biochemist and biologist Elaine Gottschall. Elaine developed the diet to help manage the symptoms of Crohn’s disease, celiac disease, chronic diarrhoea, colitis, cystic fibrosis and diverticulitis.

FODMAP is an acronym that stands for Fermentable, Oligosaccharides, Disaccharides, Monosaccharides and Polyols. They are all forms of carbohydrates that absorb water in the small intestines and pass through to the large intestine where they rapidly ferment as naturally occurring bacteria consume them. This fermentation process releases gas, and it’s this combined with the excess water that causes abdominal pain, discomfort, flatulence, bloating and many other gastrointestinal symptoms related to Irritable Bowel Syndrome (IBS) and Small Intestine Bacterial Overgrowth (SIBO). When a person follows a Low FODMAP diet they aim to eat foods that are low in these types of carbohydrates. For more details please read my post “Low FODMAP – A basic guide”.

What is a SIBO SCD diet used for?

It may seem like a silly question but the SIBO SCD can actually be used for a number of gastrointestinal disorders, not just SIBO as the name suggests. IBS, ulcerative colitis, crohn’s disease, celiac disease, and Inflammatory Bowel Disease (IBD) to name a few, can all benefit from following this diet.

How it works

People who suffer with IBS, SIBO and other gut issues tend to find it difficult to break down complex carbohydrates such as starchy and sugary foods. This leads to food being undigested in the gut allowing bacteria and yeast to feed off it, leading to bacterial and yeast overgrowths (an unbalanced intestinal flora). This goes on to cause a chain reaction of excess toxins and acids which can cause irritation, damages cells and stops food from absorbing properly.

By eating foods that are easily digested, it means the body is able to process/ digest it properly; therefore bacteria and yeast are not able to feed from it. This can help to rebalance the intestinal flora, reduce inflammation and allow the right digestion processes to occur. As the gut begins to heal and functions better, symptoms are reduced and in some cases can be completely healed.

The basics; what you can and can’t eat

The idea is to avoid starchy foods, eat low fibre and low fermentable fruits and vegetables. Be conscious of portion sizing, don’t eat any raw foods for the initial interim period and wait 4 hours between meals (Ideally 5 hours but this can be tricky for people who might work shifts etc, so 4 hours is acceptable).

There are a number of useful websites that list the types of SCD foods that you can/ can’t eat as well as low to high FODMAPs. Just remember that a SIBO SCD is a combination of BOTH these diets so if you are looking at a low FODMAP list, there may be foods on there that are NOT SCD allowed. It’s the same with SCD lists; you will need to cross reference them with a FODMAP list.

The top website listed below, has a list that is SIBO SCD foods– a combination of SCD and FODMAPS. It may help if you print this off.

SIBO Diet Recipes – this website has a SIBO SCD allowed/not allowed foods AND FODMAP list. That means that you won’t need to check it against a FODMAP list.

Dr Axe

Breaking the Vicious Cycle has a FULL A-Z list of SCD foods

Health Through Diet has a SCD foods list

Foods to eat include meat* and fish, fats, lactose free dairy, nuts, seeds, allowed fruit and vegetables and other ‘legal’ items.
*not including bacon, chorizo, sausages or meats that will have other ingredients in.

Foods to avoid include all grains (including quinoa and oats), all sugars, soy, tubers (arrowroot, parsnips, tapioca) no gums or thickeners such as carrageen or guar gum, no garlic or onions, no mucilaginous foods such as flaxseed, chia, aloe or astragalus.

Where to start

There are two elements to the diet the first part is the SCD side, where foods are split into ‘illegal’ and ‘legal’ food groups. You need to remove all the foods from your diet that fall into the ‘illegal’ category. These foods will remain the same no matter how long you have been on the diet.

However, the second part of the diet – the FODMAPs change after you have been on the diet for some time and you are feeling the benefits (e.g. are symptom free).

FODMAPs are split into three categories – low, moderate and high. When you start the diet you will be eating all the foods in the low category. Some foods are considered low FODMAP if you eat a small portion, but if you eat more than the recommended portion size it can fall into the moderate category. For example 1 cup of cabbage is considered low FODMAP, whereas more than one cup will be considered moderate FODMAP.

Once you have adapted to eating SIBO SCD and are feeling better you can start to re-introduce or increase some of the FODMAP foods, by eating from the moderate category.

It can take time to re-introduce or increase foods, as it’s possible that you may react to some of them. You need to reintroduce one food item at a time so that you can monitor your response to them. Start with a very small portion and if you feel ok eating it (e.g. have no symptoms such as flatulence and bloating) then next time try increasing the portion size.

If you do notice your symptoms flaring after reintroducing a FODMAP then you need to discontinue this food and mark it down as one of the foods you don’t tolerate. If you notice your symptoms flare only after eating the larger portion size then make a note of the amount you were able to eat without any issues.

Many of the websites I have read suggest two weeks as the initial period (the time before you can start to reintroduce foods). However I would say 2 weeks as a minimum and see how you feel. If, like me, you have serious chronic health issues, it can take your body a lot longer to adjust/ respond to things.

My Story

If you have been following me for some time you will know that I’m not new to the world of elimination diets. In 2013 my private specialist doctor recommended a Stone Age diet (eating clean, unprocessed foods) to help manage my symptoms of Myalgic Encephalopathy. In 2014 she also recommended I follow a ketogenic diet – combining it with Stone Age eating. The idea was that by eating clean, I was able to avoid chemicals, preservatives and additives in foods, which can stress the body and digestive system. By adding in the ketogenic diet I was able to push my body into using fat a fuel, which can help with mitochondrial function as well as my gut issues.
After antibiotic treatment for Lyme disease my gut issues got worse and the NHS just confirmed the IBS label I had already been given (I had private testing that confirmed I had SIBO).
In 2016 I embarked upon an Auto Immune Protocol (AIP) diet to help identify foods that I was sensitive to. I combined this with a Low FODMAP diet which is recommended for IBS. I found combining these ways of eating with the ketogenic aspect to be incredibly complicated and quite stressful, so I ditched being ketogenic and focused on just being low carb.

I’ve found AIP and Low FODMAP incredibly helpful in identifying some of the foods that I am sensitive to, and it’s helped reduce my symptoms massively. However I’ve struggled with reintroductions – finding that some days, I react to foods and other days having no reaction. I got really fed up and frustrated and felt like I needed to go back to the drawing board and start again.

Originally when I first looked at diets specific to SIBO, I had bookmarked a few websites for the SIBO Specific Carbohydrate Diet. I decided to have another read through and seeing that it had a 75% chance of improvement (1), I felt it was the best next step for me.

I will still have to remain AIP for the mean time, as it takes time to reintroduce foods, but my aim is to add in all the foods that are on a ‘NO’ AIP list, that are compliant with a SIBO SCD.
If you want to know more about my health and the diets I have been using to help manage my symptoms then take a look at the following posts. You can also follow me on Instagram and Facebook.


Food Diary – I recommend a food diary because it can really make the difference in spotting if you respond to something. I’ve been following a variety of elimination diets for a while now and I have been terrible at keeping a food diary (i.e. haven’t logged a thing – eeek!). I recently decided I needed to get a better grip of things and purchased a Low FODMAP diary from amazon. It’s been a life changer, helping me to recognise when I react to foods. The book I purchased (2) was £4.99 but you could easily buy a plain note pad from a pound store and use that instead. You just need to note down what time you eat, what you eat and whether any symptoms arise after eating it. It also helps to note down bowel movements, water intake, and stress levels.

The Four Dark Horsemen (3) – The SCD lifestyle website suggests that there are four possible ‘bad guys’ that are the reason you may not see any improvement on the SIBO SCD. They are listed as Dairy, Eggs, Nuts and Excessive fruit/ honey.

These are all foods that I have already eliminated on the AIP diet and am still slowly working on reintroducing them (eggs and nuts only). I would recommend eliminating them when you start the SIBO SCD diet and get it out the way. I say this because you may be surprised to find out that you react to them when you later reintroduce. Through the AIP diet I have discovered a number of foods that I react to that I would have sworn I would be fine eating! It gets easier to recognise flare ups or reactions when you have been symptom free for a while.

Timings – It’s recommended that you leave 5 hours (although 4 hours is acceptable) between meals and the reason for this is so that it gives the gut a chance to digest your meal and have what’s known as a ‘housekeeping wave’ (4).

The intestine has two modes that it can be in – either an eating mode (which is self-explanatory) or cleaning mode (housekeeping wave) which is when it cleans up and empties into the colon. A housekeeping wave occurs every 90 minutes and is a strong repetitive motion (like a wave) that pushes leftover indigestible material into the colon. However if you are always eating and snacking, the intestine will be constantly in eating mode and indigestible materials will be left to ferment and be snacked on by bacteria!

Meal Planning It might be a struggle to eat meals with such a large time gap, especially for those who may have set work breaks or those who may eat at certain times (e.g. with children after school).

As a result I highly recommend doing a bit of meal planning, so that you are able to leave enough time between meals to allow for a cleaning wave. For example, it might help to work backwards if you know that you need to eat your last meal at 6pm. This would mean that you would have lunch at 1pm and your breakfast at 8am.

Whatever way round you work it, it helps to plan what meals you eat each week – including breakfast choices because it means you won’t have to spend time faffing and trying to decide what to eat (which often leads to snacking or picking!).

It helps to find a few recipes and get the ingredients in that you need to make them, before you start the diet. That way you are less likely to fall off the waggon or cheat.
I will include a list of websites with recipes on so that you can take a look. Just remember that some of the recipes will be for when you have reintroduced foods, especially desserts that may use honey to sweeten them.


The websites listed below are good for information, lists, recipes and other useful resources (such as useful supplements and testing etc). The first two websites are also listed above, but these links take you to the recipe sections.

SIBO Diet Recipes
Dr Axe
The Healthy Gut
Bridgetown Nutrition
SCD Lifestyle
My SIBO Recipes

Final Note

If you have found this information useful or want to add anything that you think will help others, please comment below. I always appreciate feedback and additional information – it not only helps me, but it helps other readers too.


(1) The Vicious Cycle – Elain Gottschall; http://www.breakingtheviciouscycle.info/p/about-the-diet/

(2) Amazon – Low FODMAP Food Diary – https://www.amazon.co.uk/Low-FODMAP-Food-Diary-Digestive/dp/1911492055/ref=sr_1_1?ie=UTF8&qid=1498658576&sr=8-1&keywords=fodmap+diary

(3) The Four Dark Horsemen – SCD Lifestyle; http://scdlifestyle.com/2011/03/what-to-do-when-the-scd-diet-isnt-working/

(4) Cedars Sinai Medical Centre – Low Fermentation / SIBO diet; http://www.siboinfo.com/handouts.html


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