1The Alimentary Journey

Irritable Bowel SyndromeIn Pregnancy and Beyond

Janice Joneja, Ph.D., RD

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Definition of Irritable Bowel Syndrome

• Irritable bowel syndrome (IBS) tends to be an umbrella term for a variety of bowel disturbances of unknown origin

• Sometimes called:

– “irritable colon”

– “spastic colon”

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Symptoms of IBS

• Symptoms include:– Change in bowel habit

• often alternating constipation and diarrhea– Abdominal bloating and distension– Sometimes abdominal pain, frequently relieved

by defecation– Feeling of incomplete defecation

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IBS Characteristics

• There is usually no sign of structural damage to the wall of the intestine (frequently indicated by blood in the stool)

• Weight loss or nighttime fever are not experienced• A diagnosis of irritable bowel syndrome is made

when all organic disease has been ruled out by appropriate medical tests

• The Manning Criteria or the Rome (I, II or III) classification system are often used for diagnosis

_____________Drossman 2006

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Rome II Criteria for Diagnosis of IBS

• Abdominal pain or discomfort for 12 weeks or longer over the past 12 months

• Plus two of the following:– Relief of discomfort with defecation– Association of discomfort with altered stool

frequency (diarrhea, or constipation, or alternating)

– Associated discomfort with stool form (hard, soft, loose, liquid etc)

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Diagnosis of IBS in Pregnancy

• Many women already have IBS before entering pregnancy

• When symptoms of IBS arise during pregnancy same criteria for diagnosis applies– However, accuracy of Rome criteria not tested during

pregnancy

– Rule out alarm symptoms of organic disease: • Blood in the stool

• Weight loss

• Fever (especially night-time)

• Abdominal masses

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Tests for IBS in Pregnancy

• Used to rule out other causes of symptoms:– Blood count– Inflammatory mediators (sedimentation rate)– Stool analysis for infections in diarrhea-

associated symptoms• Ova and parasites

• Bacterial pathogens

_______________Sanders et al 2001

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Tests for IBS in Pregnancy:Differential Diagnosis

– Rule out celiac disease:• Anti-endomysial antibodies

• Anti-tissue transglutaminase (tTGA) antibody

– Lactase deficiency:• Hydrogen breath test

• Blood glucose or galactose

– Thyroid function

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Classification of IBS

• IBS can be classified according to the predominant bowel symptoms: – IBS with constipation predominant features

(IBS-C)– IBS with diarrhea predominant features (IBS-

D)– IBS with alternating symptoms of diarrhea and

constipation (IBS-A)

________________________Hammerle and Surawicz 2008

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Etiology of IBS

• While the exact pathophysiology of IBS is unclear, suggested causes include:– Genetics– Post-inflammatory changes– Hormone level fluctuations– Psychosocial factors– Side-effects of medications– Use of oral antibiotics– Food allergy and food intolerances

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Gastrointestinal Pathology:Inflammation

• Infection (post-infective (PI)-IBS)• Pathology in the digestive tract, resulting in

inflammation, cell damage and hyperpermeability– Inflammatory bowel disease– Crohn’s disease– Celiac disease

• Surgical procedures in the digestive tract resulting in persistent inflammation, change in microbial flora or other disturbances

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Hormones Associated with GI Tract Function

• Hormonal fluctuations– Menstrual cycle– Pregnancy– Thyroid function

• Hormonal changes during pregnancy may modify gastrointestinal function

• Estrogen and progesterone increase– Affect GI functions eg gastric slow wave rhythm– May delay colonic transit, especially during the third

trimester– May affect nociception (perception of pain)

__________Hasler 2003

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Pain Perception and Hormones

• Women exhibited reduced thresholds for pain during certain phases of menstrual cycle: assumed hormonal involvement2

• Hormone changes in pregnancy may alter the perception of pain and increase the distress associated with IBS

_______________2Mayer et al 1999

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Neurological Factors

• Psycho-social factors causing dysregulation within the brain-gut axis:– Psychiatric disorders– Stress

• Motor dysfunction

• Intestinal motility disorders

• Sensory dysfunction

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Alteration in the Microbial Flora of the Digestive Tract

• Change in types of micro-organisms in the large intestine due to:– Oral antibiotics– Other oral medications– Change in substrate (ie type of food passing into the bowel)

• Alteration in microbial flora results in:– Different products resulting from the action of micro-

organisms on undigested food material:• Gases • Organic acids• Others

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Composition of the Diet

• Suggested dietary causes include:– Food allergy (immune-mediated responses)– Food intolerance (non-immunologically-

mediated reactions)- Food composition:

• Inadequate fiber• Inappropriate fibre• High fat levels• Gas-producing foods• Carbonated beverages

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Mechanisms Responsible for Symptoms

• Key factors in functional gastrointestinal disease (FGID) resulting in symptoms include:

– Inflammation • Resulting from release of inflammatory mediators

– Increased sensitivity to pain• Neuropeptides (tachykinins) generated by the

central nervous system interact with neurokinin receptors on the spinal cord

• May also result from a response to inflammatory mediators (e.g. histamine)

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Mechanisms Responsible for Symptoms (continued)

– Motility dysfunction• Resulting from changes in autonomic

nervous system signals• Resulting from products of microbial

fermentation

– Fermentation• Of undigested food in the large bowel• As a consequence of abnormal motility• As a consequence of altered microbial flora

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Altered Motility in the G.I. Tract

• Altered speed of food passing through the G.I. tract can result in disturbance of the normal process of digestion and absorption of nutrients:– Increased speed results in :

• Incomplete breakdown of food components in the small intestine

• Increase in fluid retention in the colon leading to diarrhea

– Decreased speed leads to increase in:

• Fermentation of undigested food remaining in the colon

• Decrease in fluid in the colon and constipation

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Gender-related Differences in GI Tract Function

• Colonic transit generally slower in women than men– May be affected by phase of menstrual cycle1

• GI tract symptoms increase in the late luteal and menses phases of the cycle

• Gastric emptying tends to be slower in women

_______________1Turnbull et al 1989

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GI Tract Motility Changes During Pregnancy

• Normal hormonal changes that occur during pregnancy cause changes in GI tract function1

– One third of pregnant women report an increase in stool frequency

– 38% report constipation• Prolonged oro-cecal transit in third trimester

of pregnancy2 contributes to constipation

_____________2Wald et al 1982

__________1Hasler 2003

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Fermentation

• All food materials not absorbed through the lining of the small intestine pass into the large bowel

• Millions of bacteria colonise the organ• Perform “end-stage digestion”• Products of microbial activity can be important

nutrients:– some B vitamins (pantothenic acid; biotin)

– vitamin K

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Causes of Intestinal Symptoms: Carbohydrates

• Non-digested carbohydrates pass into the large intestine causing:– Osmotic imbalance: causes excess fluid in the

lumen of the large bowel resulting in loose stool– Increased bacterial fermentation resulting in

production of:• organic acids (acetic, lactic, butyric, propionic)

– increase osmotic imbalance

• gases such as carbon dioxide and hydrogen – cause bloating and flatulence

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Symptoms of Excessive Fermentation of Carbohydrate

• Patients complain of abdominal fullness, bloating, and cramping pain, sometimes within 5-30 minutes, sometimes several hours after ingesting carbohydrate

• Watery diarrhea occurs from 5 minutes to 5 hours after ingestion

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Examples of Fermentation of Undigested Sugars:Lactose Intolerance

• Milk sugar, lactose, is digested by lactase enzyme produced in the cells lining the digestive tract

• Lactose is a disaccharide (double sugar) which cannot be absorbed through the lining of the digestive tract until it is broken down into its two single sugars (monosaccharides):

– Glucose

– Galactose

• Lack of lactase reserves makes lactose

particularly vulnerable to maldigestion

Therapeutic Management of IBS

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Clinical Approach to IBS• Optimal treatment of IBS remains to be defined• Based on treatment of the prevalent symptoms:

does not address the cause (which in most cases is either unknown or not amenable to treatment)

• When pain predominates:– Antispasmodic medications

• Diarrhea predominant:– Loperamide to reduce bowel frequency

• Constipation predominant:– Soluble fibre

• Antidepressants (e.g. SSRI) to control pain and relieve associated depressive symptoms

_____________Drossman 2006

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Drugs in Pregnancy

• Contraindicated: if at all possible drugs should be avoided:– Balance risk vs benefit

• Recommended:– Education (reassurance and attitude to distress)– Stress reduction– Dietary modification

___________Hasler 2003

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Probiotics in Management of IBS

• IBS involves dysfunction in a variety of complex interactive mechanisms

• Many of these involve microorganisms:– Interaction between different micro-organisms

within the microflora– Interaction of microorganisms with the host– Interactions between microorganisms and the

immune tissues within the gut resulting in inflammatory processes that lead to:

– Hyperpermeability of the intestinal lining

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Probiotics and IBS• Probiotic management of IBS is in its

infancy• Studies demonstrate the possible value of

probiotics in short-term management of specific symptoms of IBS, namely:– Diarrhea– Constipation– Abdominal bloating

• Specific strains, dose, and viability remain to be determined

________________________Quigley and Flourie 2007

______________Parkes et al 2010

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Examples of Preliminary Studies

• Bifidobacterium infantis shows some evidence of:– Reducing flatulence– Retarding colonic transit

• Dosage, duration, and extent of clinical benefits in IBS remain to be determined

____________Kim et al 2005

____________Reid et al 2008

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Synbiotic and Constipation• 2008 study: women between the ages of 18 and 55

with and without functional constipation • Activia yogurt containing 10(8) UFC/g of

Bifidobacterium animalis and fructoligosaccharide– 2 units/day of Activia or a lacteous dessert without

probiotics (control) for a period of 14 days

• Results:– Improvement in the quality of the stools– Reduced perception of straining effort– Reduced perception of pain associated with defecation

________________De Paula et al 2008

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Probiotics in Management of IBS:Lactose intolerance

Lactobacilli, bifidobacteria and Streptococcus thermophilus, assist in reducing the symptoms of lactose intolerance

• Produce the enzyme beta-galactosidase (lactase) in yogurt

• Microbial lactase breaks down lactose• The fermented milk itself delays gastrointestinal

transit, thus allowing a longer period of time in which both the human and microbial lactase enzyme can act on the milk lactose.

________________Montalto et al 2006

Diet in the Management of Irritable Bowel Syndrome

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Role of Food in IBS

• Food does not cause IBS• Food passing through “damaged organ”

continues or exacerbates the condition• Food interacts with gastrointestinal tissues

in several ways:– Immunologically– Physiologically– Biochemically

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Contributory Factorsin IBS

• It is likely that a variety of factors are contributing to the symptoms in an individual sufferer

• A practical approach to the dietary management of IBS takes into account as many of these factors as possible

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2007 Study, Canada

• Diet is the primary factor manipulated by women with IBS to manage their condition

• Few participants received assistance from primary health care professionals

• All participants indentified food/beverages that caused exacerbation of their symptoms

• All participants had individual triggers

• “One size does not fit all!”________________Jamieson et al 2007

_______________Fletcher et al 2008

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Dietary Fibre and IBS

• Increased dietary fibre has been a mainstay of therapy for patients with IBS following an article in 1984

• The basis for this was thought to be:– Decrease in colonic pressure– Acceleration of oro-anal transit

_____________Cann et al 1984

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Fibre and IBS: Current Recommendations

• Investigations indicate that increased fibre is of little value in treatment of IBS: there was little difference between treatment group and placebo, and no relief of abdominal pain

• Insoluble fibre (corn, wheat bran) may worsen the symptoms1

• Abnormal bacterial fermentation of the undigested fibre in the colon can cause excessive gas production, bloating and abdominal pain and worsen the clinical outcome in IBS2

______________________

1Bijkerk et al 2004

_____________________________

2Haderstorfer et al 1989

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Fibre and IBS: Current Recommendations

• The American College of Gastroenterology Functional Gastrointestinal Disorders Task Force recommends use of fibre in patients with constipation, but not for the treatment of IBS

Brandt 2002

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General Guidelines for Dietary Management of IBS

1. Reduce inflammation in all parts of the digestive tract

– Avoid inflammatory triggers

2. Reduce the amount of fermentable substrate passing into the colon

– Increase digestion and absorption in the small intestine

Joneja 2004

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Dietary Management of IBS (continued)

Triggers and exacerbators of inflammation include:– Allergens– Chemicals that enhance release of

inflammatory mediators (e.g. tartrazine; benzoates)

– Raw foods– Alcohol– Caffeine and other methylxanthines

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General Instructions

• It is important to eat a balanced diet complete in all essential nutrients

• Eat three meals a day, with two or three snacks as desired

• For each food avoided, substitute one of equal nutritional value

• Supplemental micronutrients (vitamins and minerals) should be considered especially during pregnancy and lactation

• Choose ones without additives (colour, sugar, preservatives)

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Dietary Guidelines: Milk

AVOID: All milk and milk products• Eliminate:

– Milk - Yogurt– Cheese of all types - Butter– Any food containing milk solids or derivatives

• Consume protein to level usually consumed as milk products

• Add calcium and Vitamin D supplements to age-appropriate level during pregnancy and lactation:– Vitamin D: 5 mgm/day– Calcium: Age 14-18: 1,300 mg/day

Age 19-50: 1,000 mg/day

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Dietary Guidelines:Grains

• AVOID: Specific cereal grains and flours: wheat, rye, oats, barley, and corn

• Use alternative grains to provide equivalent nutrients:– Millet – Quinoa

– Tapioca – Amaranth

– Arrowroot – Rice

– Sago

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Dietary Guidelines:Fruit and Vegetables

COOK All: Vegetables (including salad vegetables)FruitsFruit and vegetable juices

– Raw vegetables, raw salads, raw fruit, raw juices, are not allowed

– Corn is avoided• Substitute with:

– Tinned fruit– Pasteurized juices

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Dietary Guidelines:Spices and Herbs

AVOID: Spices (root, seed, bark of plant); examples:– Cinnamon – Coriander seed

– Curry spices – Mustard seed

– Chilli seasoning spices – Pepper – Others

Substitute with:

• Herbs (leaves and flowers); examples:– Thyme – Mint – Others– Sage – Parsley– Rosemary – Basil– Oregano – Coriander leaves

• Cooked garlic and ginger are allowed, if tolerated

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Dietary Guidelines:

DisaccharidesAvoid:

• Sucrose (Table sugar)– Granulated– Castor– Demarara– Brown– Syrup of any type

Substitute with:– Honey– Fructose (“fruit sugar”; laevulose)Unless there is evidence of fructose

malabsorption– Glucose (dextrose) is allowed but is not very

sweet

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Dietary Guidelines:Legumes

AVOID: Legumes with indigestible, hard, outer skins; examples:– Dried peas and beans– Green peas, sugar peas, lima beans, broad beans

Substitute with:– Runner beans, French beans, yellow wax beans, green

beans– Dried legumes without outer skins (lentils, split peas) – Legumes ground into flours (chick pea flour, soy flour,

black or red bean flour)

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Dietary Guidelines:Nuts and Seeds

AVOID: Whole nuts and seeds• Eat as “butters” (paste) only; examples

– Peanut butter (without any added sweeteners)– Almond butter– Cashew butter– Sesame butter and tahini– Sunflower seed butter– Pumpkin seed butter

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Dietary Guidelines:Meat and Fish

AVOID: “Deli meats” such as:– Fermented sausages (salami, bologna, pepperoni,

hot dog wieners)– Smoked meat or fishCook all meats and fish from fresh or frozen sources– No breaded, battered, sweet cured meats– No smoked fish or meat– Do not add cream saucesAvoid excess fat in meats, especially in diarrhea

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Dietary Guidelines:Fermented Foods and Beverages

AVOID: Alcoholic beverages of all typesAVOID: Vinegar and foods containing vinegar:

– Pickles– Relish– Prepared mustard– Ketchup

AVOID: Fermented foods such as:– Sauerkraut– Soy sauce

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Dietary Guidelines:“Irritating” Foods and Beverages

AVOID: Caffeine and benzoatesAvoid coffees and regular tea

– Herbal tea (without spices) are allowed. Some decaffeinated coffees contain chemicals to which sensitive individuals react

– Note: If several cups of coffee or black tea are consumed per day, reduce intake gradually; sudden total withdrawal can produce unpleasant side effects

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Dietary Guidelines:Vitamin and Mineral Supplements

To ensure adequate intake of micronutrients, a multivitamin/mineral supplement is recommended

Supplement should be free from: • Wheat• Yeast• Lactose• Corn• Additives such as artificial colours, flavours, and

preservatives.

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Dietary Guidelines (continued)

– People differ in their degree of reactivity to some of the restricted foods

– Many individuals do not react adversely to vinegar and fermented foods

– Some people can drink coffee and eat chocolate but react adversely to tea (probably indicating benzoate sensitivity rather than a reaction to caffeine)

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General Guidelines

• The diet is initially followed for four weeks• If no improvement, keep a careful record of foods

consumed and symptoms experienced for a further seven days

• Based on the food/symptom record, increase restrictions for a further two weeks

• If still no improvement, proceed to reintroduction of foods

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Dietary Management of IBS:The Next Stage

If significant improvement is achieved open food challenge may be initiated

• Use sequential incremental dose challenge (SIDC) to determine sensitivity and limit of tolerance to each eliminated food in its purest form

• Symptom-free status may be maintained by avoiding the culprit foods and obtaining complete balanced nutrition from alternative sources

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Invitation to Further Information

www.allergynutrition.com

Joneja, J.M.Vickerstaff. Digestion, Diet and Disease: Irritable Bowel Syndrome and Gastrointestinal Function. Rutgers University Press, Piscataway, New Jersey 2004