Although it may seem daunting to have to follow a liquid diet for 2-3 weeks, in fact this is usually fairly straightforward, as it is clear just what you should be eating at each meal. Most people find that symptoms may temporarily get worse as bacteria in the bowel die off because they lack substrates to live on, but after the first few days their symptoms steadily improve. Such improvement is very good for morale, and makes the difficulties of dieting seem well worth-while!

However it is not realistic to stay on an elemental diet indefinitely, and the next phase of food testing may be quite demanding.  The foods which cause problems may vary greatly from one person to another and there is unfortunately no simple test which might show which foods to eat and which to avoid. Food reactions in Crohn’s disease (CD) are not due to allergy and the usual allergy skin and blood-tests are therefore not helpful. We introduced the LOFFLEX diet to try both to simplify and to speed up the process of food testing. 

Our work with elemental diets had shown us that fat (especially long-chain triglycerides) is a problem, and we knew that fibrous foods were often fermented by the intestinal micro-organisms. We also had experience of the foods which had upset people who were using the Elimination diet to sort out food intolerances.  This enabled us to construct the LOFFLEX diet.

‘LOFFLEX’ stands for – LOFat/ Fibre Limited EXclusion diet. This diet excludes all those foods which are most likely to cause food intolerance and must be followed for approximately 2-4 weeks. The LOFFLEX diet limits fat to 50g per day, fibre to 10g, and also excludes a few foods which are neither fatty nor fibrous, but have been shown sometimes to cause difficulties, such as yeast and coffee.

A diary needs to be kept during this period recording food eaten and symptoms suffered. Liquid diets such as Elemental 028 Extra remain useful as supplements if weight gain is desired or if the full range of recommended foods is not being eaten.

However, it is important that if you are considering dietary treatment of CD you do it with the agreement of your doctor, and with the supervision of a registered dietitian.

Most people find that they can move on smoothly from the elemental diets to the LOFFLEX diet. This considerably reduces the time they need to stay on a liquid diet, and reduces the number of foods which must subsequently be tested. These foods can therefore be tested more slowly, taking 4 days for each, and a whole week in the case of wheat which is often particularly slow to produce symptoms. 

However, it must be appreciated that the LOFFLEX diet is based on probabilities rather than certainties and that a small minority of patients may be upset by foods which are allowed. The diet must therefore be followed for two to three weeks, to ensure that there are no unexpected reactions, and during that time it is important to keep an accurate food and symptom diary to enable the source of any symptoms which may develop to be accurately identified. 

If the patient is symptom free at the end of the LOFFLEX diet period, food testing may begin. If severe symptoms arise on the LOFFLEX diet it is sometimes necessary to go back to the liquid diet and then restart food testing once the symptoms have settled again.

We have found that apart from its use in CD, the LOFFLEX diet may be very valuable in other disorders which involve abnormal bacterial overgrowth in the alimentary tract.  These include persistent pouchitis after ileo-anal anastomosis, and oro-facial granulomatosis.  Patients suffering from pseudo-membranous colitis caused by Clostridium difficile may also be much more comfortable following the LOFFLEX diet until the antibiotics taken to eradicate the infection have their full effect.

Further details of the LOFFLEX diet can be found in Inflammatory Bowel Disease: The Essential Guide to Controlling Crohn’s Disease, Colitis and other IBDs by Professor Hunter. provides general information only and should not be regarded as a substitute for medical advice from your own doctor or healthcare provider.
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