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Inflammatory Bowl Disease (IBD)

Food Choices Is a Complicated Business

When first diagnosed with Crohn’s disease or ulcerative colitis, there are many choices you will need to start making. For many people with Crohn’s disease or ulcerative colitis, collectively called inflammatory bowel disease (IBD), the mere act of eating can no longer be taken for granted. Because IBD affects the digestive system, diet and nutrition are impacted in different ways. Food choices can become more complex since certain foods may make symptoms worse, therefore attention must be paid to avoiding foods that worsen or trigger IBD symptoms. In addition, it is important to learn how to make healthy food choices, replacing nutritional deficiencies and maintaining a well-balanced nutrient-rich diet.

About Crohn’s and Ulcerative Colitis (UC)

Both cause chronic inflammation in the gastrointestinal (GI) tract, where digestion and absorption of nutrients take place. Inflammation is the body’s response to tissue injury. Normally, inflammation helps protect the body from harmful bacteria and viruses, damaged cells or irritants, but in IBD, the immune system reacts abnormally, leading to inflammation. Inflammation weakens the ability of affected GI organs to function properly. Ongoing inflammation leads to symptoms such as abdominal pain and cramps, diarrhoea, rectal bleeding, weight loss and fatigue.

The Gastrointestinal System

To understand the relationship between diet, nutrition and IBD, it is helpful to know how the gastrointestinal tract processes food. The GI tract consists of a series of mostly hollow organs beginning at the mouth, followed by the oesophagus, stomach, small intestine, colon, rectum and anus.

The roles of the gastrointestinal system are:

  1. Digestion—the breakdown of food

  2. Absorption of nutrients and water

  3. Elimination of waste

How IBD Affects Digestion

When you suffer from IBD, inflammation in the organs of the digestive tract can affect the process of digestion. Inflammation in the small intestine of a person with Crohn’s disease can interfere with the digestion and absorption of nutrients. Food that is not completely digested may cause diarrhoea and abdominal pain when it travels through the colon. In a person with ulcerative colitis, the small intestine works normally, but the inflamed colon does not absorb water properly, resulting in diarrhoea, heightened need to have a bowel movement and increased frequency of bowel movements.

How IBD impacts Keeping Healthy Nutrition

People with IBD may have difficulty maintaining healthy nutrition for a variety of reasons, including disease symptoms, complications and medication.

Symptoms: During times of flare-up: diarrhoea, urgency to have a bowel movement, abdominal pain, nausea, vomiting, blood in the stool, constipation, loss of appetite, fatigue and weight loss can negatively impact nutrition.  Severe diarrhoea can cause dehydration, robbing the body of fluids, nutrients and electrolytes (sodium, potassium, magnesium and phosphorus).


People with IBD often have reduced appetite as a result of nausea, abdominal pain or altered taste sensation. This can make it difficult to consume sufficient calories and nutrients.  Furthermore, the need to have frequent bowel movements may cause a person with IBD to shy away from eating too much to avoid symptoms. This may lead to unhealthy weightless.  Furthermore, the inflammatory process in Crohn’s disease and ulcerative colitis can result in increased consumption of stored energy and a breakdown of the body’s tissues, often resulting in weight loss despite adequate caloric intake.

Another possible symptom of IBD is rectal bleeding resulting from sores (ulceration) that form in the inner lining of the intestinal tract, leading to blood loss. Chronic blood loss can cause anaemia.


  • Malabsorption of nutrients- Inflammation in the small intestine of a person with Crohn’s disease can interfere with the absorption of nutrients. Amino acids (from proteins), fatty acids (from fats), sugars (from carbs), vitamins and minerals are mostly absorbed from the last two sections of the small intestine (jejunum and ileum).  The degree of malabsorption depends on how much of the small intestine is affected by Crohn’s disease, whether the disease is active or in remission and if any portion of the intestine has been surgically removed. Generally, the malabsorption and nutrient deficiencies tend to be more significant if larger sections of the small intestine are inflamed or removed. If a significant portion of the ileum is inflamed or removed, the absorption of fat-soluble vitamins (A, D, E and K) and vitamin B12 will likely be reduced, malabsorption of fatty acids may occur, resulting in abdominal cramping, diarrhoea, malabsorption of fat-soluble vitamins and weight loss.

    Bile acids or bile salts (responsible for aiding in absorbing fats and making the stool brown in colour) can also be mal-absorbed if the ileum is inflamed or removed. This can result in excess bile salts being transported to the colon where they cause increased fluid secretion in the colon and watery diarrhoea.  Patients with ulcerative colitis may have less significant nutrient deficiencies; however, weight loss and anaemia can be extensive due to severe diarrhoea and blood loss.

  • Growth delays and Decreased bone mineral density - Some children with IBD fail to grow at a normal rate, very likely because of the impact of intestinal inflammation on nutrition (as described above in “Symptoms”), long-term use of corticosteroid medications (which have a negative impact on bone growth) and poor nutrition in general.  To minimize the negative effects of IBD on growth, good eating habits, adequate caloric intake and control of the underlying disease are very important. It is also important for children to be monitored carefully for proper weight gain and growth. Decreased bone mineral density (low bone mass) is common in children, adolescents and adults with IBD. Severe forms of decreased bone mineral density (osteoporosis) may lead to bone fracture. This may be due to insufficient calcium intake, poor absorption of calcium, vitamin D (needed to help the body use calcium) deficiency, decreased physical activity, inflammation and/or long-term use of medications such as corticosteroids.

  • Strictures - In some people with Crohn’s disease, chronic inflammation in the intestine can cause the walls of the intestine to narrow and also form scar tissue. The scar tissue can cause narrowing of the passageway, restricting food passage through the intestine. Narrowing of the intestine is called a stricture. Dietary modifications such as a low fibre or liquid diet along with medication may be necessary if the stricture is mostly inflammatory. If the narrowing is mostly scar tissue, surgery may be required to widen the narrowed section or remove it. A low-fibre or liquid diet is often prescribed until surgery is performed.

Medications:  Medications tend to work better in people with good nutritional basis. Certain medications used in IBD may also have adverse effects on nutrition. For example, corticosteroids may affect nutrition by increasing appetite, increasing serum glucose levels, increasing the risk for diabetes and affecting electrolyte (mineral) levels.   Although steroids can be effective for reducing inflammation, they can have potential adverse effects (they can slow the process of new bone formation and accelerate the breakdown of old bone ) when used for extended periods.

Steroids also interfere with calcium absorption and may also decrease bone mineral density as previously discussed. Most bone loss occurs in the first six months of corticosteroid use.


Supplementation with calcium and vitamin D may help protect bone health, especially while patients are treated with steroids. Patients on sulfasalazine and methotrexate should receive supplemental folic acid. Cholestyramine, which is used sometimes to treat bile acid diarrhoea, may decrease the absorption of fat-soluble vitamins. Check with your healthcare professional if any of your medications could interfere with your nutrition.

Healthy Diet and Nutritional Choices

Diet and nutrition are important aspects of IBD management.

“Diet” refers to the foods we eat. “Nutrition” is a term that refers to properly absorbing food and staying healthy. A well-balanced diet with adequate intake of protein, carbohydrates and fat, as well as vitamins and minerals, is necessary for nutrition.  Having an active chronic disease such as IBD, tends to increase the body’s requirements for calories, nutrients and energy. During flare-ups, it may be difficult to maintain adequate nutrition, which is essential in order to improve overall wellness, promotes healing and immunity, increases energy levels and may alleviate some gastrointestinal symptoms.

Is there an IBD Diet?

There is no evidence suggesting that any particular food or diet causes, prevents or cures IBD. There is no one special IBD diet. A few diets are advertised specifically for managing IBD, but generally speaking, an anti-inflammatory diet can help reduce symptoms and also pain.

It is important to note that people may report success with one type of diet or another in alleviating symptoms, but there has been no scientific evidence supporting these diets. Additionally, the diets may be very restrictive and difficult to follow.  Researchers are continuing to study the interaction between diet and IBD. Currently, dietary recommendations are generally aimed at easing symptoms during flare-ups and ensuring an overall adequate intake and absorption of nutrients, vitamins and minerals.

May I Eat “junk” food?

People who suffer from IBD face specific challenges, and a healthy diet is high on the list of issues to take into account. Although certain ‘junk’ foods can contain some healthy ingredients, junk food should be consumed in moderation.

Developing a Customised Diet For You

Many people with IBD can consume a normal diet during times of disease remission but may need to alter their diet during flare-ups. Other, such as patients with intestinal strictures, will need to stay on a modified diet until the stricture is successfully treated.

The customised diet should be based on:

  1. Symptoms (diarrhoea, constipation, abdominal pain, etc.)

  2. Whether the person is in remission or experiencing a flare-up

  3. Physical location of disease

  4. Presence of narrowing of the small intestine (strictures)

  5. Prior surgeries

  6. Whether there are any specific nutritional deficiencies (such as iron, calcium or vitamin D deficiency)

Impact of Certain Foods

During flares, certain foods or drinks may irritate the digestive tract and cause symptoms to worsen. Not all people with IBD are affected by the same foods, and it may be necessary to experiment to discover which foods affect symptoms the most. Keeping a food journal may help keep track how your diet relates to your symptoms and identify trigger foods.

Possible Food intolerances & Trigger Foods

  • Food allergies and intolerances - Neither Crohn’s disease nor ulcerative colitis is caused by a food allergy. Yet some people with IBD may also have food allergies. The most common foods causing an allergic reaction are milk, eggs, peanuts, tree nuts (e.g., walnuts, almonds, cashews, pistachios and pecans), wheat, soy, fish and shellfish. It is important to distinguish between an actual food allergy and food intolerance.  A food allergy is associated with an immune system response and can cause a severe and life-threatening reaction, while a food intolerance can cause GI symptoms. The majority of people suffer from food intolerances rather than food allergies.  Elimination diets (avoiding trigger foods) are used to determine which foods must be avoided or minimised. This involves systematically removing foods or ingredients that may be causing symptoms. It is important to do this under the supervision of a healthcare professional to ensure it is done correctly without damaging your nutrition. When eliminating foods, it is important to substitute other foods, that provide the same nutrients. For example, when eliminating dairy products, be sure to obtain calcium and vitamin D from other sources.

  • Fibre - Dietary fibre is found in plant foods, such as fruits, vegetables, nuts and grains. It is vital for health and for digestion. For many people with IBD, consuming fibre during times of disease flare-ups or strictures can cause abdominal cramping, bloating and worsening diarrhoea. But not all sources of fibre cause these problems, and some sources of fibre may help with IBD symptoms.  Soluble (able to dissolve in water) fibre helps absorb water in the gut, slowing down the transit time of food. It can help reduce diarrhoea by forming a gel-like consistency and delaying evacuation of the intestine. Insoluble (does not dissolve in water) fibre is more difficult to digest because it pulls water into the gut and makes food move quicker through the gut. It is a harder coarser fibre found in the skins of foods such as apples and seeds. Consuming insoluble fibre can aggravate IBD symptoms by causing discomfort resulting from bloating, diarrhoea, gas and pain. When there is severe inflammation or narrowing, consuming insoluble fibre can lead to worsening symptoms and a blockage in the intestinal tract.

    Most foods contain a combination of fibres, so cooking, peeling and removing seeds are important for patients who are in a flare-up and need to reduce their intake of insoluble fibre.

  • Lactose - Lactose intolerance is a condition in which the body does not properly digest lactose, the sugar present in milk and dairy products. Some people with IBD may be lactose intolerant. In addition, some people with IBD may only have problems with lactose digestion during a flare-up or after surgical removal of a segment of the small intestine. It is important to find  out if you’re lactose intolerant. Poor lactose digestion may lead to cramping, abdominal pain, gas, diarrhoea and bloating. Because the symptoms of lactose intolerance may mimic those of IBD, it can be difficult to distinguish between the two. A simple test called a lactose breath test (or Hydrogen breath test) can diagnose this condition. Not all people with IBD are lactose intolerant.

    The severity of symptoms will depend on how much lactose an individual can tolerate. Lactase is the enzyme responsible for breaking down the lactose in dairy products. Lactase supplements can be taken along with milk to help digest it. There are also lactose free dairy products.  Fermented dairy products such as yogurt and kefir may be more easily tolerated and therefore a better choice. Hard cheeses are generally well tolerated because they contain a minimal amount of lactose.

    Milk and dairy products are important sources of nutrients, especially calcium. Therefore, people who limit or eliminate milk and dairy products entirely from their diet should obtain calcium from other food sources or from supplements.

  • High-fat foods – Foods high in fast, such as butter, margarine and cream, may cause diarrhoea and gas if fat absorption is incomplete. These symptoms are more common in people who have inflammation in the small intestine or who have had large sections of the small intestine surgically removed.

  • Gluten- Gluten is a protein which is found in grains including wheat, rye and barley products.  Some people with IBD may be sensitive to gluten and have gluten intolerance. These people may also have symptoms of abdominal bloating and diarrhoea after eating gluten-containing food, therefore avoiding gluten is advisable to them. If you suspect that you might have gluten intolerance you can ask your healthcare professional to perform a food intolerance test which also detects gluten antibodies.  You may also consider being tested for Celiac disease which is  an inflammatory reaction to gluten and different from gluten intolerance.

  • No-absorbable Sugars - Sugar alcohols, such as sorbitol and mannitol, may cause diarrhoea, bloating and gas in some people who suffer from IBD. These ingredients are often found in sugarless chewing gums and sweets. Sorbitol may also found in ice-cream and in several types of fruits, such as apples, pears, peaches and prunes, including the juices of these fruits.

  • FODMAPs – (Fermentable Oligo-Di-Monosaccharides and Polyols) These are sugars that are found in certain carbohydrates and sugar alcohols. If someone has intolerance to foods high in FODMAPs it could result in excessive gas, bloating, diarrhoea and cramping.

    Foods that are high in FODMAPs include:
    Fructose—fruits, honey, high fructose corn syrup.
    Oligosaccharides are carbohydrates with a small number of simple sugars. These can be found in certain vegetables, cereals and legumes
    Lactose from dairy products
    Polyols found in sugar alcohols (sorbitol, mannitol, xylitol) and certain fruits

    The low FODMAP diet is an elaborate eating plan that should be initiated with the help of a nutritionist or dietitian.

Managing IBD with a Healthy Diet

There is no single diet or eating plan that suits everyone with IBD, and dietary recommendations must be customised to the individual.

However, there are some basic principles and guidelines on how and what to eat, especially during flare-ups. People with IBD should maintain a diverse and nutrient-rich diet. When experiencing symptoms, it is advisable to:

  1. Eat smaller portions and more frequently

  2. Try relaxing whilst you are eating

  3. Avoid trigger foods

  4. Limit insoluble fibre intake (i.e., seeds, nuts, beans, green leafy vegetables, fruit and wheat bran)

  5.  Reduce the amount of greasy or fried foods


Keep in mind that all IBD patients have different food intolerances. One may be sensitive to spicy food while another might be sensitive to chocolate. During Flares


The following recommendations are aimed at reducing uncomfortable symptoms, replacing lost fluids, preventing vitamin and mineral deficiencies, and providing adequate caloric intake.

Everyone should drink plenty of fluids for good health. The amount of water to drink depends on several factors, such as physical activity, weather and health conditions.  Generally speaking:

  1. Drink slowly rather than fast. Also avoid using a straw. Drinking fast and using a straw may introduce air into the digestive system, which may cause discomfort. 

  2. Alcoholic and caffeinated drinks dehydrate the body, so make sure to replenish. Alcohol abstinence may not be required, but moderation is recommended. Ask your health care provider about alcohol consumption.


A good indication of an adequate fluid intake is urine which is between pale to clear.

If you’re experiencing diarrhoea you may be at risk for dehydration. Replacing fluids and electrolytes is advisable. Drinking more water is usually effective for rehydrating.

Excess sugar can cause more diarrhoea due to the pull of water into the gut. Fruit juices used for rehydration and replenishing of vitamins and electrolytes should be diluted with water.

Selecting and Preparing Fibre Sources

As previously mentioned, fibre can occasionally cause problems for people with IBD, especially during flare-ups. It is advantageous to soluble fibre intake during a disease flare-up and reduce the intake of insoluble fibre.

For tips for better food selection and minimising the negative effects of certain fibres during inflammation return to the table above.


Get Enough Calcium

Calcium consumption is especially important for people with IBD. The recommended dietary allowance (RDA) of calcium is 1,000 mg per day for men and women ages 19 to 50 and men ages 51 to 70. It is 1,200 mg per day for women over age 51 and men over age 70. Children ages 4 to 8 should consume 800 to 1,000 mg per day, and children ages 9 to 18 should consume 1,200 to 1,500 mg per day.

To meet your calcium requirements without a supplement, aim to eat at least three to four servings of calcium-rich foods daily. Sources of calcium include milk (regular, lactose-free, calcium- fortified almond or soy), yogurt, cheese, calcium-fortified orange juice and canned fish.

Dark green vegetables contain less calcium but they have great nutritional value and are excellent sources of folic acid. If you aren’t getting the recommended amount of calcium in your diet, you can add a calcium supplement.

Maintain Adequate Caloric Intake

Meeting the body’s calorie and protein demands is essential to prevent tissue wastage and weight loss. However, getting adequate calories can be challenging when one of the symptoms is loss of appetite.

Caloric needs may increase during times of stress, including inflammation, fever and diarrhoea. If your weight begins to drop, try adding about 250 to 500 calories more per day, and talk to your healthcare provider for additional strategies for maintaining healthy weight.

Other Tips and Tricks:

Food Journal - Because each person with IBD will have different reactions to foods and these may vary over time, it is helpful to maintain a food journal to keep track of what you eat. The journal can help you identify foods you are unable to tolerate during a flare. It can also reveal whether your diet is providing an adequate supply of nutrients. Tracking foods along with symptoms will be helpful when speaking to your healthcare professional. A practical app that can help you with tracking can be found here.

Managing Social Eating – Socialising often involves food and drink. Knowing that you have to go out to dinner or to a social event involving food can be stressful for some people with IBD. However, there are ways to get through dining out and

“social eating.” There is no “IBD-safe” menu but there are techniques and strategies for making dining out a positive experience.

  • Don’t go out feeling too hungry, because you are likely to make wrong food choices.

  • Don’t be afraid to make special requests. Most restaurants are very aware and considerate.

  • Call ahead if you have specific questions or review the menu ahead of time online. This way, you can identify potential challenges ahead of time. 

  • Eat smaller portions—perhaps an appetizer or a half-size portion.

  • When in doubt, keep it simple. Choose boiled, grilled, broiled, steamed, poached or sautéed options, and limit sauces and spices.

  • When going to a party, bring an item you know you can eat and bring enough for others too. 

  • Ask your doctor about products that help to manage or reduce symptoms, including anti-diarrhoeal medications, antispasmodics or lactase supplements.

If you find yourself avoiding social situations or struggling with eating or the thought of eating, speak with your healthcare professional, family or friend who might be able to help you manage eating and IBD better.


Generaly speaking, most vitamins, minerals and other nutrients may be obtained from food.

However, many people with IBD are advised to take supplements to make up for a deficiency or to prevent a deficiency from taking place. This is because IBD, as previously discussed, can prevent a person from maintaining adequate nutrition.

Supplements that may be required:

  1. Calcium – See above.

  2. Vitamin D- Essential for good bone formation and for the processing of calcium. The recommended daily allowance for vitamin D depends on age. Vitamin D is contained in many foods, but it can also be obtained through sun exposure. Vitamin D deficiency is one of the most common nutritional deficiencies in people with Crohn’s disease. Therefore, it is recommended to consult your healthcare professional who can help determine your supplementation need based on the level of deficiency.

  3. Folic acid -  Some drugs used to treat IBD, such as sulfasalazine and methotrexate, interfere with the absorption of folic acid, one of the B vitamins. IBD patients who take sulfasalazine or methotrexate are advised to take a folic acid supplement of 800 mcg to 1 mg per day.  All pregnant women, including women with IBD, are advised to take folic acid supplements (at least 400 mcg daily) to prevent spina bifida and other neural tube defects in infants. Folic acid is particularly important for pregnant women with IBD who take sulfasalazine. Pregnant women taking sulfasalazine should take 2mg per day (Consult with your GP on your particular needs).

  4. Vitamin B12- is absorbed in the ileum. People with Crohn’s disease that affects the ileum and those who have had surgery to remove 50cm or more of the ileum may have vitamin B12 deficiency because they are unable to absorb enough of this vitamin from their diet. A blood test can measure the amount of vitamin B12 in the blood.  Use sublingual B12 in tablet form or spray.

  5. Iron- Blood loss from inflammation and ulceration of the intestines can occur in some people with IBD. Blood loss can cause anaemia. Blood iron levels can be measured with a simple test. If they are found to be too low, iron supplements may be given. Discuss the appropriate dose with your healthcare professional.  Iron supplements should be taken in two or three doses during the day. Liquid iron supplements are more easily absorbed and less likely to cause constipation than tablets. Iron can also be given intravenously if oral iron is not well tolerated.

  6. Zinc- Patients with extensive disease in their small intestine are at risk for zinc deficiency.  People who develop short bowel syndrome (a condition that sometimes occurs after a significant portion of the small intestine has been removed or damaged) are also at risk. Symptoms of zinc deficiency include a rash, changes in taste, smell and sight, and difficulty with wound healing. If a deficiency is suspected, your healthcare professional will recommend zinc supplement and will can advise you regarding proper dosage.

  7. Vitamins A, D, E and K- These are fat-soluble vitamins. Patients with malabsorption may be at risk for fat-soluble vitamin deficiency. Your healthcare professional can help determine if you need additional supplementation of these vitamins.

  8. Omega-3 fatty acids- These are essential fats found in fatty fish, flaxseed, walnuts and fortified products. Including these foods provides valuable nutrients. There is no evidence to date that omega-3 fatty acids significantly reduce inflammation of IBD to improve symptoms, but some patients choose to take a fish oil supplement. These supplements should be stopped before procedures/surgery because they may prolong bleeding time.

  9. Probiotics- These are microorganisms contained in foods or supplements that provide beneficial health effects. Yogurt, which contains live bacteria, is an example of a probiotic food. Under normal circumstances, so-called “good” bacteria are present in the intestines where they aid digestion and help protect the intestine from harmful bacteria. Some studies show that in people with IBD, there are fewer “good” bacteria. The idea behind taking probiotic supplements and eating foods containing live bacteria is to restore the normal balance of microorganisms in the intestines. Lactobacillus preparations and live-culture yogurt are recommended for everyone. Some preparations of probiotics have been evaluated for specific types of IBD. Your healthcare professional may help you decide if a specific probiotic is needed.

  10. Prebiotics - As the intestinal microbiota has been linked to the pathogenesis of IBD, probiotic treatment is an avenue for therapeutic intervention. Another method is via the administration of prebiotics. Prebiotics are described as “non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one, or a limited number of bacteria in the colon, thus improving host health”.  The rationale behind prebiotic use is to elevate the endogenous numbers of beneficial bacterial strains including lactobacillus and bifidobacterium [76, 77]. This increase then imparts the beneficial effects seen by probiotic administration, including an increase in short chain fatty acid (SCFA) production, particularly butyrate, which is deficient in the colonic mucosa of UC patients.  Butyrate provides fuel for enterocytes, prevents pathogenic adherence and production of anti-bacterial substances, and decreases luminal pH. Based on these protective mechanisms, administration of SCFA enemas have been shown to be effective for left-sided UC that is refractory to medical therapy. Common prebiotics include inulin, resistant maltodextrin, oligosaccharides such as fructooligosaccharide (FOS) and galactooligosaccharide (GOS). The body of research involving the use of prebiotics to treat IBD is not currently as extensive as that regarding probiotic therapy.  

  11. Polyphenols - These are phytochemicals that are found in food substances produced from plants.  Polyphenols are separated from essential micronutrients in that a deficiency state has not been identified; nevertheless, these chemicals are believed to play a biologically-active role and have been shown to be potentially immune-modulating. For IBD, downregulation of inflammatory mediators and nuclear factor kappa beta (NFkB) are broad mechanisms of action for polyphenols’ therapeutic effects.  Although numerous polyphenols have been identified, five in particular have evidence of benefit for animal and human studies in IBD including: resveratrol , epigallocatechin , curcumin, quercetin and Boswellia Serrata

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