In order to maintain good health, a well-balanced and nutritious diet is essential for absolutely everyone, but is even more so for those with IBD, which can interfere with the absorption of nutrients from food and increase energy demands on the body. A good diet can help you cope better with IBD by building up your body’s reserves of energy and essential nutrients.
To understand the importance of diet and nutrition in the management of IBD, it’s useful to have some knowledge of the function of some major parts of the GI tract.
The main processes of digestion and absorption take place in the small intestine. Most of the breakdown of food occurs in the first segment of the small intestine, the duodenum. The middle segment, the jejunum, digests carbohydrates. The final segment, the ileum, breaks down fats and absorbs vitamin B12 and bile salts. Any remaining waste matter moves into the large intestine (colon) where water is absorbed back into the bloodstream. The leftover waste, which includes fibre and bacteria, is formed into faeces and expelled through the anus.
On this page:
- Why is diet so important in IBD?
- What exactly is a good diet?
- Can a good diet prevent or cure IBD?
- Is there a special IBD diet?
- Is diet equally important for Crohn’s disease and ulcerative colitis?
- Is IBD caused by an allergy to food?
- Is it true that milk will make the symptoms of IBD worse?
- How much fluid do I need to drink?
- Do I need to take vitamin and mineral supplements?
- Is there anything special that can be done during flare-ups?
- High energy/protein supplements
- Low or modified fibre diets
- Liquid Diets
- ‘Probiotics’ can help in IBD. Can you explain what these are?
- What about fish and fish oil?
Why is diet so important in IBD?
Food is fuel for the body. Eating a well-balanced diet that includes items from all major food groups (see next page) provides all the essential nutrients or building blocks that the body requires each day to grow, repair damage, generate energy, and protect itself from illness.
Those with IBD are at risk of becoming malnourished, especially those with Crohn’s disease in the small intestine. The main reasons for this are:
- Loss of appetite due to nausea, abdominal pain, or altered taste sensations, leading to inadequate food intake.
- Increased need for nutrients and energy by the body because of chronic inflammation. This is especially true during active stages of the disease.
- Poor digestion and malabsorption of dietary protein, fat, carbohydrates, water, and various vitamins and minerals. Those with Crohn’s disease of the small intestine, or those who have had all or parts of their small intestine surgically removed, might be at higher risk of malabsorption.
Diet and good nutrition play a key role in managing your IBD as they are important for restoring the body to health. A well-balanced diet can help you through episodes of active disease, keeping you in much better condition. Good nutrition also increases the chances of a better response to medications or a better outcome if surgery is required to remove part of the intestine.
Younger people who develop Crohn’s disease or ulcerative colitis before the onset of puberty might experience a delay in growth. To some extent, this is related to the presence of chronic disease in the body, but is most often the result of inadequate food intake. Good nutrition and adequate energy intake for one’s age and gender are therefore highly important in children and adolescents with IBD.
What exactly is a good diet?
A good diet is one that contains items from all major food groups. Eating a variety of foods from each of these food groups every day will help ensure that you’re meeting all your needs for energy and essential nutrients such as carbohydrates, protein, and fats, as well as vitamins and minerals.
Breads and cereals
- Foods in this group include bread, breakfast cereals, pasta, rice, cracker biscuits, muffins, and crumpets. These are all good sources of fibre—especially the wholemeal and wholegrain varieties—and resistant starch. Resistant starch is starch that is not digested in the small intestine, but passes into the large intestine where it fuels bacterial fermentation. The products of this fermentation provide fuel for the gut wall lining and help maintain the overall health of the large intestine.
- Breads and cereals provide valuable energy for the body in the form of carbohydrates, and also supply protein, vitamins (B-group and folic acid), and minerals (zinc and iron).
Fruits and vegetables
- Starchy vegetables such as potato and corn are good sources of carbohydrate. All other green, yellow, orange, white and red vegetables are good sources of many vitamins and minerals.
- Fruits contain carbohydrates and are good sources of energy, fibre, and antioxidants. Fruits also contain many essential vitamins and minerals such as folic acid, vitamins A and C, iron, magnesium, and vitamin B6.
Milk and milk products
- This group includes dairy products such as milk, yoghurt, and cheese, as well as calcium-fortified soy milk and soy yoghurt. These foods are an important source of calcium and also provide energy, protein, and zinc.
- Calcium is essential to bone health and is especially important for those who require corticosteroid treatment. Meeting your daily calcium needs
Meat and meat alternatives
- This group includes lean meat, poultry, fish, eggs, nuts, tofu, and legumes (beans, chickpeas, lentils). These foods are an important source of protein and energy.
- Lean red meat provides an excellent source of iron and zinc. Including lean red meat in your diet three to four times each week will help you to meet your iron requirements.
- Meat, poultry, fish, and eggs also contain vitamin B12, which might be poorly absorbed in people who have Crohn’s disease in the last (terminal) part of the ileum.
Fats and oils
- Polyunsaturated or monounsaturated vegetable oils and margarine are important sources of energy. They also contain many essential fat-soluble vitamins such as vitamins A, D and E. These are often called good fats because they have no adverse effect on cholesterol levels. Canola margarine, canola, and olive oil are recommended.
- It is important to distinguish polyunsaturated or monounsaturated fats from saturated fats, which are mainly animal fats such as butter, meat drippings, ghee, and palm oil. Saturated fats have no known benefits to human health and increase cholesterol levels.
- Foods that are high in sugar such as soft drinks, lollies, honey, and jam tend to be recommended only in small quantities. They are sources of instant energy and can be useful to those who have experienced significant weight loss and are trying to regain weight. On the other hand, those who are well and are gaining too much weight should avoid these extra-energy foods.
Can a good diet prevent or cure IBD?
To put it simply: diet is not the cause of IBD nor is it the cure.
There is little evidence to suggest that dietary factors cause IBD. Likewise, it is not possible to make your condition go away permanently by adding or eliminating certain foods from your diet, or by eating only particular types of food. Some find that a particular food aggravates their symptoms; eliminating this food can make a positive difference. For most though, the key to managing their condition is in eating a well-balanced diet that includes items from all major food groups. Good nutrition improves overall health status, supports the healing process, and can enhance the response to medications. A poor diet makes it more difficult for the body to counteract the effects of IBD.
Is there a special IBD diet?
Most people with Crohn’s disease or ulcerative colitis can tolerate all types of food and don’t require any dietary restrictions. In fact, avoiding certain foods or eliminating an entire food group can contribute to nutritional deficiencies.
During flare-ups of disease, some find that a bland, low-fibre diet is easier to tolerate than one that contains high-fibre or spicy foods. Low-fibre diets are those that avoid the skins and seeds of fruits and vegetables, as well as nuts, dried fruit, seeds, bran, and whole grains. These diets tend to stimulate less secretion of intestinal fluids and cause less contraction in the small and large intestine, helping control symptoms such as abdominal cramps and diarrhoea.
In cases of Crohn’s disease when an area of the small intestine has become narrowed (i.e., a stricture has developed), a very low-fibre or even a liquid diet might be necessary to minimise the discomfort of abdominal cramping.
For each and every person with IBD, individual experience is the most useful guide to selecting the types of food that can or cannot be tolerated. Foods that cause problems for one person with IBD might not affect another at all. If you follow the foods-to-avoid advice of others with IBD, including those on the Internet, you might find yourself eating a highly-restricted diet unnecessarily and increasing your risk of malnutrition. Remember, too, that foods you have to avoid during flare-ups might not be a problem when your disease is stable and you feel well.
In general, achieving and maintaining overall good nutrition far outweighs any sort of blanket recommendations about diet, or even—unfortunately—your own personal preferences. If you have a particular liking for a specific type of food that has caused you problems in the past, you are the one who can best decide whether the enjoyment of eating it from time to time is worth the possible symptoms such as pain, cramping, and bloating.
Is diet equally important for Crohn’s disease and ulcerative colitis?
The short answer is yes. The longer answer is that those with Crohn’s disease might have more specific issues with diet, depending on the location of inflammation.
Those with inflammation limited to the large intestine—including those with Crohn’s disease—absorb nutrients from food normally, so they tend to have a lower risk of weight loss and malnourishment, although a good diet is of course still important.
Those with Crohn’s disease that involves the small intestine can have quite specific nutritional problems. Despite eating enough food of the right kind, they might still be unable to absorb essential nutrients. The degree to which absorption is impaired depends on which segments of the small intestine are involved, and/or whether any part of the intestine has been removed by surgery.
For example, Crohn’s disease in the jejunum (the middle segment of the small intestine) can impair the absorption of carbohydrates. If inflammation is limited to the very last part of the small intestine, the terminal ileum, it is likely that only the absorption of vitamin B12 will be affected. If most or all of the ileum is inflamed, significant malabsorption of fat can also occur; and if the upper regions of the small intestine are also involved, it’s possible to have deficiencies of many different nutrients, minerals, and vitamins.
In addition, some IBD medications, especially sulfasalazine, can interfere with the absorption of folic acid, which is essential in the prevention of cancer and birth defects.
For these reasons, those with Crohn’s might have highly individualised dietary needs, and/or require supplements to replenish nutrient stores. A dietitian can provide individualised advice and help plan meals to optimise nutritional intake for a tailored Crohn’s disease diet. While less specific, the importance of a ulcerative colitis diet is equal to that of an individual with Crohn’s.
Is IBD caused by an allergy to food?
Many people with IBD mistakenly think they’re allergic to food because they associate their symptoms with eating. It is important to know that Crohn’s disease and ulcerative colitis are not caused by a food allergy. The hallmark symptoms of IBD such as abdominal cramps, diarrhoea, and a sense of urgency to move the bowels are a non-specific reaction to the presence of inflammation in the GI tract. So there is no need to avoid any particular type of food because of a presumed allergy to food. Those who have a true allergic reaction to foods (e.g., peanuts, strawberries, etc.) might experience anything from a mild skin rash (hives) to an anaphylactic shock (a sudden and severe drop in blood pressure and difficulty in breathing). Food allergies are a completely separate issue and should not be confused with IBD.
On the other hand, many people might not be able to tolerate certain foods (e.g., onions, milk, etc.) and can develop symptoms such as burping, bloating, or flatulence (gas).
(Some tend to confuse food intolerance with food allergy. They are completely different, and your dietitian can help explain the difference in greater detail.)
If you’ve come to know through experience that you have difficulty tolerating specific types of foods, it’s best to avoid these whenever possible. You must ensure however that you replace these foods with alternatives to maintain an adequate diet.
New research suggests that some people with IBD might also experience symptoms of irritable bowel syndrome (IBS) and can benefit by avoiding foods that are termed FODMAPs. FODMAPs are a group of carbohydrates—fructans, galacto-oligosaccharides (GOS), polyols, fructose and lactose—that are poorly absorbed and are fermented by bacteria. The fermentation results in extra water moving through the bowel and excessive gas production. Some examples of high-FODMAP foods are:
Dietary FODMAPs should not be restricted unless you experience symptoms of diarrhoea, bloating, abdominal pain, and flatulence that continue after your specialist has determined that your IBD has stabilised. A dietitian experienced in FODMAPs is essential in this situation. There is some information about a low-FODMAP diet on the Internet, but much of this is outdated. You can visit the Monash University Low FODMAP Diet website for reliable advice: https://www.monashfodmap.com/.
Is it true that milk will make the symptoms of IBD worse?
The assumption that milk and milk products such as cheese, ice cream, etc. can worsen the symptoms of IBD is unfounded. Instead, it’s now well known that many people (not just those with IBD) are unable to properly digest lactose—the sugar present in milk and most milk products—because they’re lacking the digestive enzyme lactase, which is normally present in the small intestine. Undigested lactose can lead to cramping, abdominal pain, gas, diarrhoea, and bloating.
The symptoms of lactose intolerance can mimic the symptoms of IBD, often making it difficult to tell whether it is IBD or dairy that is causing the problem. A simple procedure called a lactose-tolerance test or a lactose breath test can determine whether or not you are lactase-deficient. If you are, it might be necessary to use low-lactose milks and yoghurts and milk-free products, or suitable calcium-containing substitutes. Additionally, a lactase supplement that breaks down lactose can be added to many dairy products so that they no longer cause symptoms. It is also important to note that most cheeses are low in lactose and can be safely consumed on a low-lactose diet. Your dietitian can provide further advice.
Anyone able to tolerate milk and milk-based products should include these in their diet as they are a good source of nutrition, especially protein, and are by far the best source of calcium. Supplemental calcium might need to be taken if milk and milk products are removed from the diet. Again, in this case, it’s best to speak to your dietitian. Lactase deficiency that becomes worse after bouts of diarrhoea can improve once the gut repairs. If even small amounts of milk can be tolerated at a time, lactose intolerance can be improved.
How much fluid do I need to drink?
Any condition with chronic diarrhoea increases the risk of dehydration if fluid intake does not keep up with the fluid loss. The risk of dehydration in IBD can be worsened by vomiting and/or poor food intake.
Dehydration and loss of body salt can cause weakness and easy fatigue, so it is important to consume plenty of fluids, especially in warmer weather conditions. Aim for six to eight glasses (250ml) of fluid per day (total of 1.5 to 2 litres), including lots of water, and increase this amount as the outside temperature increases or if you are physically active.
Those with Crohn’s disease and ulcerative colitis have a greater chance of developing kidney stones. This is partly related to dehydration, but is a very specific issue among those with Crohn’s disease who’ve had all or part of their ileum surgically removed. The resection of 60 cm or more of the ileum can result in increased absorption of oxalate, which then reacts with calcium in the urine to produce calcium-oxalate kidney stones. People who have had part of their ileum removed might need to reduce the amount of oxalate in their diet by avoiding certain foods known to be high in oxalate. There is a long list of these food items but some examples include: spinach, cocoa, beans, rhubarb, beetroot, almonds, cashews, wheat bran, chocolate, instant coffee, and tea. In some cases, medications
to prevent the formation of calcium-oxalate kidney stones might be needed. For most, the easiest and most efficient way to prevent the development of kidney stones is to drink plenty of fluids in order to keep the urine as dilute as possible.
Do I need to take vitamin and mineral supplements?
Because vitamin and mineral deficiencies are relatively common among those with IBD, taking a standard multivitamin and mineral tablet each day might be beneficial. The need for more specific supplements depends on the extent and location of disease. Your treating specialist will advise you of any specific requirements you might have.
Is there anything special that can be done during flare-ups?
During IBD flare-ups, it might be necessary to make some dietary changes to help control symptoms and minimise any detrimental effects IBD has on your overall nutritional status and health. Dietary changes might also be required if you have a bowel obstruction, have undergone surgery or, in some cases, need to rest the bowel and give it an opportunity to heal.
Generally, any changes to your diet or supplements that need to be taken—in addition to or in place of a normal diet—are temporary measures that last only until the inflammation is under control. These need to be carefully monitored by your clinical team to ensure that all your energy and nutritional needs are being adequately met.
High energy/protein supplements
During active stages of IBD, the energy demands on the body increase and there can be a considerable loss of protein through the wall of the small and large intestine. It could be difficult to keep up with protein intake because of symptoms such as nausea and diarrhoea. This can lead to significant weight loss and reduced protein status which could result in weakness and fatigue.
High energy/protein supplements can help provide and replenish nutrients during the times when it is difficult to eat. These supplements are available as milk-, soy-, and fruit-based drinks which provide an easy-to-take source of both energy and protein. Your dietitian should be able to advise you regarding some common food ingredients that can be used to make supplements, as well as powdered and ready-to-drink supplements.
Low or modified fibre diets
A low-fibre diet is one that contains a minimal amount of fibre or bulk. It is often used when there is active disease in the large intestine or terminal ileum, or when there is partial obstruction in the small intestine. By limiting the amount of undigested food matter (fibre) that passes through a narrowed section of small intestine and/or reaches the large intestine, a low-fibre diet can reduce irritation and decrease symptoms such as pain and abdominal cramping.
Breads (wholemeal or wholegrain), cereals, fruits, and some vegetables are foods that contain the most amount of fibre so these need to be limited in a low-fibre diet. White bread, pasta, rice, cracker biscuits, refined breakfast cereals such as Cornflakes™, Rice Bubbles™, and Special K™, as well as vegetables such as potatoes, carrots, and pumpkin are all freely permitted. Food groups such as meats, dairy products, and fats and oils are also freely permitted because they don’t contain dietary fibre. In the event that you are advised by your clinical team to follow a low-fibre diet, your dietitian can help.
Low-fibre diets tend to be used for short periods of time only, just until the inflammation has settled. High-fibre foods can then be gradually re-introduced into the diet.
Specialised liquid formulations (or enteral feeds) might be necessary if there is major bowel obstruction or severe disease, or if surgery has been done on the small intestine. Avoiding all solid food and replacing it with liquid formulations can help reduce inflammation, rest the bowel, and reduce the need for high doses of corticosteroids.
Liquid formulations have been shown to be as effective as corticosteroids in treating children with active disease and can also assist in maintaining their growth. Supplementary liquid feeding or exclusive liquid feeding for a short period can also help keep Crohn’s disease in remission.
Liquid diets are usually given for several weeks, followed by a gradual re-introduction of food and tapering off of the liquid formulations. These diets need to be carefully monitored to ensure that all your nutritional needs are being met.
Liquid formulations are consumed by mouth or fed by tube directly into the stomach or small intestine. Although these formulations still need to be digested, they are easier to digest and absorb than food. They are often lactose-free and gluten-free and some are low in fibre, making them less likely to irritate the intestines. Some formulations can be elemental, that is, they contain nutrients that are already broken down into the most easily absorbed (elemental) form, therefore giving the bowel a chance to rest. Research suggests, however, that elemental formulations have no advantage over other liquid formulations. Your clinical team will advise you. Tube feeds are usually done in hospital but, with sufficient training, can also be carried out at home.
There are several liquid formulations that are suitable to drink. The choice will depend on your needs and taste. Some liquid formulations also have flavourings to make them more enjoyable.
‘Probiotics’ can help in IBD. Can you explain what these are?
A large number of micro-organisms or bacteria live in the large intestine: some are good, others not so good. Depending on which bacteria predominate in the large intestine of a person, the health of the intestine can be affected positively or negatively.
Although there is no convincing evidence to suggest that intestinal bacteria cause IBD, it is thought that they might be contributing to the inflammatory process among those who already have IBD. At the moment, research is looking into whether changing the type and/or the level of various bacteria in the large intestine can help in the treatment of IBD.
Prebiotics are non-digestible food ingredients (fibre) such as non-starch polysaccharides (a type of carbohydrate) and resistant starch. They provide nutrients that stimulate the growth or activity of ‘good’ bacteria in the GI tract. Examples of sources of prebiotics are stalks and leaves of vegetables, outer coverings of seeds and fruits, bread, potatoes, and bananas. Bacteria in the gut use this non-digestible food matter to produce short-chain fatty acids (SCFA) such as acetate, butyrate, and propionate. These SCFA have a number of beneficial effects:
- they are used as fuel by the colon wall, liver, heart, and lungs
- they increase the absorption of electrolytes and fluid, reducing the risk of diarrhoea
- they increase the efficiency of digestion by slowing down the rate at which food moves through the small intestine.
Butyrate in particular appears to be especially useful as it is the preferred fuel of colon cells and helps to maintain their integrity. Clinical studies in patients with ulcerative colitis have shown that infusion with butyrate can result in prompt healing of the lining of the large intestine.
Probiotics are food supplements containing ‘friendly’ bacteria that change the population of bacteria in the large intestine from ‘bad’ to ‘good.’ Probiotics are available as yoghurt or yoghurt drinks and in capsule or powder formulations. Research suggests that probiotics might play a role in maintaining remission among those with IBD by acting in some important ways:
- they counteract dysfunction of the immune system by preventing bad bacteria from populating the intestinal wall
- they prevent infection by ensuring that the intestinal wall remains healthy
- they improve the production of healthy by-products, such as butyrate, in the large intestine.
Prebiotics and probiotics have different, but complementary, mechanisms. Increasing the amount of non-starch polysaccharides and resistant starch in your diet is an easy and inexpensive way to improve the health of your large intestine. Adding yoghurt to your diet is not only easy to do, it also provides an excellent source of calcium and plenty of ‘good bugs’ for your intestine.
A word of caution, however: not all probiotics are created equally. You’ll need to consider the dose as well as the strain of probiotic to determine if the therapy will be of benefit to you. Speak to your clinical team to determine the best course of action.
What about fish and fish oil?
A lower incidence of IBD has been found in countries such as Japan, where fish consumption is traditionally high. The omega-3 fats found in fish are anti-inflammatory and, whilst more research is needed for IBD, there is some evidence to suggest that fish oil can help people maintain remission longer.
You can get certain amounts of omega-3 from green leafy vegetables, walnuts, canola, and linseeds, but eating several fish meals a week is the best way of ensuring adequate intake of omega-3 fats. Fish also a great source of protein and other nutrients.
Fish oil capsules can supply much larger amounts of anti-inflammatory omega-3 fats. If you wish to take fish oil via capsules, ask your clinical team for advice as you might need a number of capsules a day. Fish oil should be taken before a meal to avoid repeating (burping) a ‘fishy taste.’