Na Psicossomática, dentro do modelo biopsicossocial, entende-se que respostas psicológicas a condições de vida podem interagir com fatores somáticos existentes, alterando a susceptibilidade e manifestação da doença, o que se mostra evidente nas somatizações, como na Síndrome do Intestino Irritável (SII), onde há alteração da motilidade intestinal e no formato das fezes, acompanhada de dores abdominais. O funcionamento mental associado às somatizações, no qual a pessoa apresenta dificuldade em relacionar o adoecimento com seu universo psicológico, é que a capacidade de simbolização, ou seja, a construção de representações mentais para o alívio do estado emocional, é afetada, cronificando as alterações fisiológicas correspondentes. O objetivo da pesquisa foi verificar se o atendimento clínico psicológico, baseado na técnica da Psicoterapia Breve Operacionalizada (PBO), com ênfase na promoção da capacidade de simbolização em relação a determinadas questões significativas, pode contribuir para a melhora dos sintomas no quadro clínico de pacientes com SII. O método utilizado na pesquisa foi o clínico-qualitativo, a partir do estudo de caso de duas pacientes adultas, com o diagnóstico principal de transtorno neurovegetativo somatoforme, portadoras de SII. A intervenção psicológica foi estruturada em três fases: 1) psicodiagnóstico, composto por entrevista semi-dirigida, Sistema Diagnóstico Adaptativo Operacionalizado (SISDAO) e Teste de Apercepção Temática (TAT), questionário de avaliação clínica da SII; 2) psicoterapia breve, em doze sessões; 3) reavaliação após seis meses. A capacidade de simbolização da primeira participante era comprometida fundamentalmente relacionada à sua dificuldade em lidar com a perda da mãe quando criança, num luto não elaborado. Apresentava dores abdominais forte, a cada dois ou três dias, evacuando uma vez ao dia e quando em crise, duas ou três vezes por dia. A segunda participante apresentou uma capacidade de simbolização que passava a ser comprometida quando o conflito entre o desejo de ser aceita por sua família, em especial sua mãe, e o de rompimento tornava-se insuportável. Apresentava dores moderada, a cada cinco dias, evacuando quatro vezes ao dia e, quando em crise, seis vezes ao dia. A intervenção clinico psicológica em pacientes com SII, baseada na técnica da PBO, com elaboração da demanda psicológica e das questões significativas que comprometiam a capacidade de simbolização, possibilitou a elaboração psicológica dos estados emocionais que estariam influenciando os sintomas da SII, de forma que contribuiu para a melhora do quadro clínico das participantes. Após seis meses da psicoterapia, a primeira participante apresentou dores fracas a cada cinco dias, frequência única de evacuação por dia, não apresentou crises. A segunda participante estava evacuando uma a duas vezes por dia, dores fracas a cada cinco dias e crises ocorriam em menor frequência. O modelo de intervenção mostrou-se vantajoso para as participantes da pesquisa, de forma que seu uso no tratamento clinico psicológica para pacientes com SII, levando em consideração as especificidades do funcionamento mental associado às somatizações, apresenta-se promissor / In Psychosomatics, within the biopsychosocial model, it is understood that psychological responses to living conditions may interact with existing somatic factors, altering the susceptibility and manifestations of diseases, which is evidenced in somatizations, such as the case of Irritable Bowel Syndrome (IBS), where there is altered intestinal motility and stool format, accompanied by abdominal pain. The mental functioning associated with somatizations, in which a person presents difficulties in associating the illness to their psychological universe, that is, the capacity of symbolization, i.e. the construction of mental representations for the relief of the emotional state is affected, cronifying the physiological changes. The research objective was to determine whether psychological clinical care, based on the technique of Operationalized Brief Psychotherapy (OBP), with emphasises on promoting symbolization capacity regarding certain significant issues, can contribute to the improvement of symptoms in clinical condition of patients with IBS. The method used in the study was the clinical-qualitative, from the case study of two female adult patients with primary diagnosis of somatoform autonomic disorder, suffering from IBS. Psychological intervention was structured in three phases: 1) psychodiagnosis, composed of semi-directed interview, Operationalized Adaptive Diagnostic System (OADS) and Thematic Apperception Test (TAT), questionnaire of clinical evaluation of IBS; 2) brief psychotherapy split in twelve sessions; 3) re-evaluation after six months. The symbolization capacity of the first participant was compromised primarily because of her difficulty dealing with the loss of her mother when a child, in a non-elaborated mourning. The patient presented strong abdominal pains, every two or three days, evacuating once a day and when in crisis, two or three times a day. The second participant presented a symbolization capacity that began to be compromised when the conflict between the desire to be accepted by her family, especially her mother, and the disruption became unbearable. She felt moderate pain, every five days, evacuating four times a day, and when in crisis, six times a day. Psychological clinical intervention in patients with IBS, based on the technique of OADS, with development of psychological demand and significant issues that compromised the capacity of symbolization, allowed the psychological development of emotional states that would influence the symptoms of IBS, so it contributed to the improvement of the clinical condition of the participants. After six months of psychotherapy, the first participant presented weak pains every five days, single daily stool frequency, no crisis. The second participant was evacuating once or twice a day, felt weak pains every five days and crisis occurred less frequently. The intervention model was advantageous to the participants, so that its use in clinical psychological treatment for IBS patients presents promising, taking into account the specifics of mental functioning associated with somatization

The present study sought to determine whether a dietary and multi-element psychological treatment (DMPT) approach in combination with standard medical treatment would offer a more efficacious therapeutic package to irritable bowel syndrome (IBS) patients than would standard medical treatment (SMT) employed alone. The DMPT group (N = 19) received a stress management training package for a 2 week period consisting of relaxation training, imagery, and bowel sound biofeedback training via a stethoscope, in addition to instructions to increase their daily consumption of dietary fiber. They also were to continue the implementation of whatever standard medical treatment they were currently receiving, be it a bulking agent, or anti-anxiety, anti-cholinergic, or anti-depressant medications, etc. The SMT group (N = 19) simply received whatever conventional medical treatment they had been prescribed.

Irritable bowel syndrome (IBS) är en av de vanligaste diagnostiserade GI-tillstånden idag och är en störning av gastrointestinalkanalen (GI-kanalen). Det finns inget botemedel mot IBS på grund av att patogenesen är oklar och därför är fokusen symtomlindring vid behandling.  De vanligaste symtom som förekommer är buksmärta, obehag i buk, uppblåsthet, utspänd buk och förändring av avföringens konsistens och frekvens. Patofysiologin är inte fullt klarlagd men en rubbning i tarm-hjärn-axeln kan leda till förändring i GI-rörelser. Neurotransmittorerna noradrenalin och serotonin (5-HT) är troligen viktiga faktorer för patofysiologin kopplad till tarm-hjärn-axeln. Syftet var att undersöka effektiviteten och säkerheten för de antidepressiva läkemedlen vid behandling av IBS. De antidepressiva som undersöktes i arbetet var tianeptin, amitriptylin, escitalopram, venlafaxin, vortioxetin och mirtazapin. De fem artiklarna som användes i detta arbete upptäcktes med hjälp av databaserna Pubmed och Onesearch. Sökord som användes var ”IBS” AND ”antidepressants” och ”IBS” AND ”SSRI”.  Alla antidepressiva visade en signifikant förbättring för livskvalitén hos deltagarna i studierna. Tianeptin, amitriptylin, escitalopram, venlafaxin och mirtazapin undersökte förändring av buksmärta och alla hade en signifikant förbättring förutom escitalopram. Escitalopram jämfördes mot rektal ballongutvidgning vid behandling hos IBS med förstoppning (IBS-C). Ballongutvidgningen visade bättre resultat än escitalopram och denna jämförelse gör det svårt att dra någon slutsats om escitalopram i arbetet. Amitriptylin, tianeptin och mirtazapin undersökte förändring av avföringskonsistensesn och frekvensen och visade en signifikant förbättring hos IBS med diarré (IBS-D). Venlafaxin visade signifikant förbättring för både lös och hård avföringsfrekvens och studerade ingen specifik IBS-grupp. Vortioxetin undersökte alla IBS-grupper och endast förändring av livskvalitén, depression och ångest vilket också gör det svårt att dra slutsats om effekt hos IBS. Det var inga av de depressiva medlen som gav allvarliga biverkningar, dock kan vissa biverkningar tolkas som mer obehagliga än andra. För vissa antidepressiva var det deltagare som avslutade studien på grund av biverkningar. Amitriptylin, tianeptin, venlafaxin vortioxetin och mirtazapin visade alla god effekt och säkerhet. Om effektiviteten ock säkerheten jämförs bland dessa har tianeptin det bästa resultatet. / Irritable bowel syndrome (IBS) is one of the most diagnosed conditions in the gastrointestinal (GI) tract today and is a disorder of the GI tract. There is no cure for IBS, which is probably due to the fact that the pathogenesis is unclear, and therefore the focus has been a symptom-relieving treatment. The most common symptoms that occur are abdominal pain, abdominal discomfort, bloating, distension of the abdomen, and change in the consistency and frequency of the stool. The pathophysiology is not fully understood, but a disorder of the gut-brain axis can lead to a change in GI movements. The neurotransmitters norepinephrine and serotonin (5-HT) are probably important factors for pathophysiology and linked to the gut-brain axis.  The aim was to investigate the effectiveness and safety of antidepressants used in IBS treatment. The antidepressants examined in this literature were tianeptine, amitriptyline, escitalopram, venlafaxine, vortioxetine, and mirtazapine. The five articles on which current litter tour work is based were obtained using the PubMed and OneSearch databases. Keywords used were "IBS" AND "antidepressants" and "IBS" AND "SSRI."  All the antidepressants examined showed a significant improvement in the participants' quality of life in the studies. The studies also examined changes in abdominal pain using tianeptine, amitriptyline, escitalopram, venlafaxine, and mirtazapine. All participants showed a significant improvement and reduced abdominal pain except when ingesting escitalopram. Intake of escitalopram was compared against rectal balloon enlargement as a treatment for IBS with constipation (IBS-C). The balloon expansion showed better results than escitalopram, and this comparison makes it difficult to draw any conclusion about escitalopram and its actual effect in different types of IBS. Amitriptyline, tianeptine, and mirtazapine investigated stool consistency and stool frequency changes and showed a significant improvement in these symptoms in IBS with diarrhea (IBS-D). Venlafaxine showed significant improvement for both loose and hard stool frequency; however, no specific IBS group was studied in this study. When ingesting vortioxetine, all different IBS groups and changes in quality of life, depression, and anxiety were examined, making it difficult to conclude about the effect of the drug in IBS. None of the antidepressant medicines produced severe side effects. However, some side effects can be interpreted as more unpleasant than others, and hence there was some loss during some studies.  Amitriptyline, tianeptine, venlafaxine vortioxetine, and mirtazapine showed good efficacy and safety. If the effectiveness and safety were to be compared between these drugs, tianeptine would be the first choice in treating IBS.

La douleur est une expérience subjective multidimensionnelle accompagnée de réponses physiologiques. Ces dernières sont régulées par des processus cérébraux qui jouent un rôle important dans la modulation spinale et cérébrale de la douleur. Cependant, les mécanismes de cette régulation sont encore mal définis et il est essentiel de bien les comprendre pour mieux traiter la douleur. Les quatre études de cette thèse avaient donc comme objectif de préciser les mécanismes endogènes de modulation de la douleur par la contreirritation (inhibition de la douleur par une autre douleur) et d’investiguer la dysfonction de ces mécanismes chez des femmes souffrant du syndrome de l’intestin irritable (Sii). Dans un premier temps, un modèle expérimental a été développé pour mesurer l’activité cérébrale en imagerie par résonance magnétique fonctionnelle concurremment à l’enregistrement du réflexe nociceptif de flexion (RIII : index de nociception spinale) et des réponses de conductance électrodermale (SCR : index d’activation sympathique) évoqués par des stimulations électriques douloureuses. La première étude indique que les différences individuelles d’activité cérébrale évoquée par les stimulations électriques dans les cortex orbitofrontal (OFC) et cingulaire sont associées aux différences individuelles de sensibilité à la douleur, de réactivité motrice (RIII) et de réactivité autonomique (SCR) chez des sujets sains. La deuxième étude montre que l’analgésie par contreirritation produite chez des sujets sains est accompagnée de l’inhibition de l’amygdale par OFC et d’une modulation du réflexe RIII par la substance grise périaqueducale (PAG) et le cortex somesthésique primaire (SI). Dans les troisième et quatrième études, il est montré que la contreirritation ne produit pas d’inhibition significative de la douleur et du réflexe RIII chez les patientes Sii en comparaison aux contrôles. De plus, les résultats indiquent que la sévérité des symptômes psychologiques est associée au déficit de modulation de la douleur et à une hypersensibilité diffuse chez les patientes Sii. Dans l’ensemble, cette thèse précise le rôle de certaines structures cérébrales dans les multiples composantes de la douleur et dans l’analgésie par contreirritation et montre que les patientes Sii présentent une dysfonction des mécanismes spinaux et cérébraux impliqués dans la perception et la modulation de la douleur. / Pain is a subjective experience comprising multiple dimensions and is accompanied by physiological responses. These responses are regulated by neural processes that play a crucial role in cerebral and spinal modulation of pain. However, the mechanisms of this regulation are still not clear and a better understanding of these processes is essential in order to treat pain effectively. The four studies of this thesis were intended to define the central mechanisms of endogenous pain modulation by counterirritation (application of two competing noxious stimuli) and to investigate the dysfunction of these mechanisms in female patients with irritable bowel syndrome (IBS). First, an experimental model was developed in which functional magnetic resonance imaging was used to measure brain activity concurrently to the recording of the nociceptive flexion reflex (RIII: an index of spinal nociceptive processes) and skin conductance responses (SCR: an index of sympathetic activation). The first study indicates that individual differences in shock-evoked brain activity in the orbitofrontal (OFC) and cingulate cortices are associated with individual differences in pain sensitivity, motor reactivity (RIII), and autonomic reactivity (SCR) in healthy volunteers. In the second study, it is shown that counterirritation analgesia produced in healthy volunteers is accompanied by the inhibition of the amygdala by the OFC, and the inhibition of the RIII reflex by the periacqueductal gray matter (PAG) and the primary somatosensory cortex (SI). In the third and fourth studies, pain and RIII reflex were not significantly modulated by counterirritation in patients with IBS in comparison to healthy controls. Furthermore, the severity of psychological symptoms was associated with pain modulation deficits and diffuse hypersensitivity in IBS patients. Together, the results of these studies clarify the functions of pain-related activity in specific brain structures and the mechanisms underlying counterirritation analgesia. Moreover, it is concluded that patients with IBS show a dysfunction of cerebral and spinal processes involved in both the perception and modulation of pain.

La barrière intestinale est la plus grande surface de contact entre le milieu extérieur et le milieu intérieur. Outre ses fonctions d'absorption des nutriments, elle exerce un rôle important de défense contre les agents indésirables (toxines, bactéries) contenus dans la lumière intestinale. Une augmentation de la perméabilité intestinale a été observée chez les patients atteints du syndrome de l'intestin irritable (SII) ou des maladies inflammatoires chroniques de l'intestin (MICI). Cette hyperperméabilité intestinale est contemporaine d'une hypersensibilité viscérale à la distension de la paroi intestinale. Des travaux récents rapportent également une augmentation de l'activité protéolytique du contenu intestinal dans le cadre de ces deux pathologies. Les estrogènes, par leurs propriétés anti-inflammatoires et leur capacité à moduler la perméabilité intestinale par activation de leurs récepteurs (REs) peuvent contribuer à l'amélioration des symptômes associés à ces pathologies digestives. Une variété de traitements médicaux a été utilisée pour la prise en charge thérapeutique du SII et de MICI. Cependant, les patients questionnent les cliniciens sur des conseils diététiques susceptibles d'améliorer leur qualité de vie. Ainsi, l'objectif de ce travail était d'évaluer les effets et les mécanismes d'action impliqués, d'un traitement par du germe de soja fermenté (SG) sur l'hyperalgésie viscérale et l'hyperperméabilité intestinale dans des modèles animaux mimant le SII et les MICI afin de proposer des futures allégations santé à ce produit. Le rationnel de l'évaluation de cet ingrédient était basé sur sa composition intéressante, à savoir, sa teneur en composés à propriétés estrogéniques (isoflavones) et sa capacité à inhiber les protéases (BBI). Dans un premier temps, nous avons montré qu'un traitement oral de 15 jours par le SG diminue de façon significative l'hypersensibilité viscérale, l'hyperperméabilité intestinale ainsi que l'augmentation de l'activité protéolytique induites par un stress de contrainte chez le rat. La diminution de la perméabilité intestinale implique une surexpression de l'occludine, protéine des jonctions serrées. De même, le traitement par du SG réduit la densité des mastocytes au niveau du côlon. Tous les effets préventifs du SG sauf ceux sur l'activité protéolytique sont estrogéno-dépendants car bloqués par l'antagoniste des REs. Dans un second temps, nous avons montré qu'un traitement préventif par le SG pendant 15 jours présente des effets protecteurs vis-à-vis d'une inflammation intestinale induite par du TNBS. Le SG atténue la sévérité de l'inflammation, l'hyperperméabilité, l'hypersensibilité et l'augmentation de l'activité protéolytique induites par la colite. Les effets anti-inflammatoires du SG sont à la fois dépendants des phytoestrogènes et du contenu de l'ingrédient en BBI. En conclusion, ces données sont prometteuses pour une future utilisation du SG dans la gestion thérapeutique du SII et des MICI comme traitement adjuvant / The intestinal barrier is the largest area of contact between the external environment and internal environment. In addition to its function of nutrient absorption, the intestinal barrier plays a key role of defense against noxious agents (toxins, bacteria) contained in the intestinal lumen. An increase in intestinal permeability was observed in patients with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). This intestinal hyperpermeability was often associated with visceral hypersensitivity to colorectal distension. Recent studies also report an increase in the proteolytic activity in patients with IBS or IBD. Estrogens, through their anti-inflammatory properties and their ability to modulate intestinal permeability by activating estrogen receptors (ERs), can play an important role in these digestive diseases. A variety of medical therapies have been used for treatment of IBS and IBD. However, patients question clinicians about dietary suggestions to improve their symptoms and quality of life. Thus, the aim of this study was to evaluate the effects and mechanisms of action involved of a treatment with fermented soy germ (SG) on visceral hyperalgesia, intestinal hyperpermeability in animal models mimicking the IBS and IBD. The evaluation of this ingredient was based on its interesting composition, i.e its content of isoflavones and a family of serine protease inhibitors known as BBI. Initially, we demonstrated that an oral treatment of 15 days by SG significantly reduces visceral hypersensitivity, intestinal hyperpermeability and increased proteolytic activity induced by acute stress in the rat. Decreased intestinal permeability is due to overexpression of occludin, a transmembrane tight junction protein. Similarly, treatment with SG reduces the density of colonic mast cells. All preventive effects of SG except those on the proteolytic activity are estrogen-dependent because blocked by the antagonist of ERs. In a second step, we demonstrated that a treatment for 15 days with SG induces protective effects against intestinal inflammation induced by TNBS. SG reduces the severity of colitis, decreases TNBS-induced hyperpermeability, hypersensitivity and increased proteolytic activity. The anti-inflammatory effects of SG are estrogen and/or BBI dependent. In conclusion, these data are promising for future use of the SG as adjuvant therapy in IBS and IBD management

<p>A diagnosis of coeliac disease (CD) in adults relies on the presence of a structurally abnormal intestinal mucosa, followed by a clear clinical remission on a gluten-free diet. There is a clear need for a rapid, simple, safe and sensitive method to determine the type and intensity of inflammation in the gut mucosa in clinical practice. The overall aims of our studies were to develop and evaluate a new technique, “the mucosal patch technique”, to characterize rectal local inflammatory process after rectal food challenge in patients with CD<b>. In study 1</b> we evaluated the potential of the new technique. The technique was well tolerated and easily applied. Pronounced neutrophil and eosinophil involvement in ulcerative colitis (UC) was demonstrated. With the high sensitivity of the technique, low-degree mucosal neutrophil activation could also be quantified in patients with collagen colitis,UC in clinical remission and in patients with irritable bowel syndrome. <b>In study 2 and 3</b> the aim was to elucidate the dynamics of the rectal inflammatory response and nitric oxide (NO) production after rectal gluten challenge. We found a pronounced neutrophil activation in coeliac patients after rectal gluten challenge. This activation was apparent 4 hours after challenge and remains for at least 48 hours. A more modest eosinophil activation started 1-2 hours later and remained at least for 48 hours. The biphasic pattern of neutrophil and eosinonphil activation after challenge suggests a biphasic inflammatory reaction. The activation of neutrophils and eosinophils precedes a pronounced enhancement of mucosal NO production. Some of our coeliac patients displayed signs of an inflammatory reaction after rectal corn gluten challenge. <b>In study 4</b> the aim was to investigate the local inflammatory reaction to gluten and cow’s milk protein in CD patients in remission. The findings indicate that not only gluten sensitivity but also cow’s milk (CM) protein sensitivity is common in CD. The data support the hypothesis that CM sensitivity may contribute to persistent symptoms in coeliac patients on gluten-free diet.</p>

A diagnosis of coeliac disease (CD) in adults relies on the presence of a structurally abnormal intestinal mucosa, followed by a clear clinical remission on a gluten-free diet. There is a clear need for a rapid, simple, safe and sensitive method to determine the type and intensity of inflammation in the gut mucosa in clinical practice. The overall aims of our studies were to develop and evaluate a new technique, “the mucosal patch technique”, to characterize rectal local inflammatory process after rectal food challenge in patients with CD<b>. In study 1</b> we evaluated the potential of the new technique. The technique was well tolerated and easily applied. Pronounced neutrophil and eosinophil involvement in ulcerative colitis (UC) was demonstrated. With the high sensitivity of the technique, low-degree mucosal neutrophil activation could also be quantified in patients with collagen colitis,UC in clinical remission and in patients with irritable bowel syndrome. <b>In study 2 and 3</b> the aim was to elucidate the dynamics of the rectal inflammatory response and nitric oxide (NO) production after rectal gluten challenge. We found a pronounced neutrophil activation in coeliac patients after rectal gluten challenge. This activation was apparent 4 hours after challenge and remains for at least 48 hours. A more modest eosinophil activation started 1-2 hours later and remained at least for 48 hours. The biphasic pattern of neutrophil and eosinonphil activation after challenge suggests a biphasic inflammatory reaction. The activation of neutrophils and eosinophils precedes a pronounced enhancement of mucosal NO production. Some of our coeliac patients displayed signs of an inflammatory reaction after rectal corn gluten challenge. <b>In study 4</b> the aim was to investigate the local inflammatory reaction to gluten and cow’s milk protein in CD patients in remission. The findings indicate that not only gluten sensitivity but also cow’s milk (CM) protein sensitivity is common in CD. The data support the hypothesis that CM sensitivity may contribute to persistent symptoms in coeliac patients on gluten-free diet.

There is a significant comorbidity between anxiety/depression and functional gastrointestinal syndromes, such as irritable bowel syndrome (IBS) and functional dyspepsia. The pathophysiological link between emotions and the gut is not known. A model of an emotional motor system (EMS) which reacts to interoceptive and exteroceptive stress has been proposed. EMS consists of specific brain structures including anterior cingulate cortex (ACC), amygdala, hippocampus and hypothalamus and mediates their communication to the rest of the body (including the gastrointestinal tract) through the hypothalamus-pituitary-adrenal (HPA) axis, the autonomic nervous system (ANS) and by a pain modulation system. The aim of this thesis was to test the EMS model by studying the relationship between symptoms of anxiety and depression and IBS-like symptoms in patients with recurrent unipolar depression, in patients with IBS and in a sample of a normal Swedish population. The peripheral limb of EMS (ANS, HPA axis and the pain modulations system) was tested in patients with IBS and control subjects. Spectral heart rate variability was used to investigate ANS function in patients with refractory IBS and in healthy controls. The HPA axis function was tested by a weight adjusted low dose dexamethasone suppression test in control subjects. The influence of catecholamine degradation on pain modulation was tested by analyzing val158met catechol-o-methyl transferase (COMT) polymorphism in patients with IBS and in control subjects. We found a significant relationship between symptoms of anxiety/depression and IBS-like symptoms in patients with recurrent unipolar depression, in patients with IBS and in a sample of the normal population. Interestingly, patients with recurrent unipolar depression in remission had no more IBS-like symptoms than controls, indicating that the gastrointestinal symptoms may resolve when depression is treated to remission. Patients with IBS have an increased mid-frequency power in rest and in supine position (after tilt test) compared to healthy controls indicating an increased sympathetic ANS drive. The symptoms of diarrhea and early satiety has in the litterature been associated to the stimulation of corticotropin releasing hormone (CRH) receptors and was also in our study related to HPA axis function tested by a low dose dexamethasone test. Interestingly both hypo- and hyperfunction of the HPA axis was related to these symptoms in control subjects. The val158met COMT polymorphism was associated to IBS-like symptoms. Control subjects with IBS-like symptoms (defined by the upper quartile in total GSRS-IBS score) had a higher frequency of the met/met and a significantly lower frequency of the val/met genotype. Also patients with IBS tended to have a lower frequency of the heterozygous val/met genotype so we conclude that this genotype may be protective against IBS/IBS like symptoms. In addition, the val/val genotype in patients with IBS was associated to diarrhea symptoms. Conclusions: Our results support the model of an emotional motor system in the genesis of functional gastrointestinal symptoms by the finding of the association of IBS-like symptoms and mood disturbances, and by finding alterations in the peripheral limbs of EMS (ANS, HPA axis and catecholamines) in subjects with IBS and IBS-like symptoms.

Laboratory analyses, essential in screening, diagnosis, treatment, and monitoring of disease, are indispensable in health care, but appropriate utilization is intricate. The overall aim of this thesis was to study the use of laboratory tests in Sweden with the objective to evaluate and optimize test utilization. Considerable inter-county variations in test utilization in primary health care in Sweden were found; variations likely influenced by local traditions and habits of test ordering leading to over- as well as underutilization. Optimized test utilization was demonstrated to convey improved quality and substantial cost savings. It was further established that continuing medical education is a suitable means of optimizing test utilization, and consequently enhancing quality and cost-efficiency, as such education was demonstrated to achieve long-lasting improvements in the test ordering habits of primary health care physicians. Laboratory tests are closely associated with other, greater, health care costs, but their indirect effects on other areas of medicine are rarely evaluated or measured in monetary terms. In an illustrative example of the effects that optimal test utilization may have on associated health care costs it was demonstrated that F-calprotectin, a fecal marker of intestinal inflammation, has the potential to substantially reduce the number of invasive investigations necessary in, and the costs associated with, the diagnosis of Inflammatory Bowel Disease. Information on trends in test utilization is essential to optimal financial management of laboratories. A longitudinal evaluation revealed that test utilization had increased by 70% in 6 years, and even though the selection of tests more than doubled, a very small number of tests represented a stable, and disproportionally large, share of the total number of tests ordered. The study defines trends and thus has potential predictive values. In summary, appropriate utilization of laboratory analyses has both clinical and economical benefits on all levels of health care.

Understanding of chronic sequelae development after infection with foodborne pathogens is limited and an increased understanding could assist with the development of more accurate burden of disease estimates. The purpose of this thesis was to determine via systematic review and meta-analysis of the published international literature, the proportion of cases of Salmonella, Campylobacter and E. coli O157 that will develop the chronic sequelae of reactive arthritis, haemolytic uraemic syndrome, irritable bowel syndrome, inflammatory bowel disease or Guillain Barré syndrome. This information can be used to increase our understanding of the relationship between infection and the development of long term health complications while providing a key piece of information for the development of accurate burden of disease estimates. / Canadian Institutes of Health Research Institute of Population and Public Health/Public Health Agency of Canada, Applied Public Health Research Chair (awarded to Jan M. Sargeant)