Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 170-194). Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 154-168).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 204 p.; also includes graphics (some col.). Includes bibliographical references (p. 196-204). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 62-72).

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Revisión por pares

M.A. / The disorder known as Irritable Bowel Syndrome (IBS) is a clinical conundrum. Of chronic magnitude, this disorder of the gastrointestinal system affects up to 20% of the population in developed countries. Yet, it remains elusive in terms of its accurate definition and diagnosis, while its origins and etiology are unknown. To date, clinical confirmation of this disorder is complex and uncertain, while medical intervention has proven to be largely unsuccessful. Symptomatology relating to IBS varies widely and is not confined to the gastrointestinal tract. Diagnoses are made on the grounds of the manifestation of certain physical symptoms such as constipation, diarrhoea, abdominal pain and distension and disordered bowel habits. The role of psychological factors in the manifestation of IBS is controversial, although many clinicians postulate IBS to be a psychosomatic disorder due to the presence of many concomitant psychological features such as anxiety and depression. By all appearances, one of the most dramatic psychosocial concomitants of IBS is stress. Research has indicated that factors such as income, social support, life stress, psychological status, coping styles and personality all play a role in terms of whether the disorder develops and how successfully or adaptively the sufferer copes with his/her disorder. In terms of a research project undertaken by the Counselling and Research Centre for Gastroenterology under the auspices of the Department of Counselling Psychology at the Rand Afrikaans University, an exhaustive investigation into the physiological and psychological concomitants of IBS was conducted. As part of this endeavour to bring IBS to the attention of the medical profession, the public at large, and the individuals who suffer from this disorder, a number of individual studies were undertaken by MA (Psychology) students as part of the larger project. These researchers attempted to highlight various essential aspects associated with IBS, the focus of which included psychopathological features, stress, abuse, coping styles and strategies, defence mechanisms, personality factors and eating disorders. A second phase of this research project is currently in operation in order to provide remediation in the form of psychotherapy and stress management to the subjects who participated in the initial research project. The focus of the present treatise aims to provide an all-encompassing integration of the various research studies referred to above. Thereafter, on the basis of the data obtained from these studies, attention turns to the identification of a psychological profile with respect to the typical patient suffering from IBS. In accordance with the scientific demands of psychosocial research, a thorough review of the literature and various theoretical explanations of IBS were conducted as part of the integrative process. A number of theoretical models were considered in terms of their application to IBS, including the Digestive Disease model; the Psychiatric model; the Psychophysiological model; a Behavioural iii model; a Biopsychosocial model and a relatively recent newcomer, the Salutogenic Orientation proposed by Antonovsky, that offers an unusual approach to health and disease. In terms of the psychological profile mentioned above, the data demonstrated interesting findings. It was ascertained that the large majority of IBS patients are women, a finding that has been internationally verified. These women tend to be married with children, well-educated and employed on a full-time basis. The emotional status of the typical IBS patient reflects varying degrees of psychopathological tendencies, while her interpersonal relationships are characteristically unstable. Demonstrating high stress levels, the IBS patient tends to utilize inadequate coping skills, while these women also report using a maladapative defence mechanism to cope with the difficulties of their lives. Furthermore, personality traits such as introversion and neuroticism have been observed in these women. Lastly, it has been noted that the typical IBS patient exhibits certain aberrant eating patterns that are characteristic of women who are diagnosed as anorexic and/or bulimic. The IBS patient experiences her physical symptoms as severely disruptive and debilitating. Living in a very stressful and demanding world, she is lonely and isolated and shows the tendency to somatize her problems in the form of a disorder that is neither life-threatening, nor results in other more serious diseases, but which causes major distress in her life.

published_or_final_version / Nursing Studies / Master / Master of Nursing

No description available.

Stress-related functional bowel disease is a common, often incapacitating, problem in humans; the symptomatology of stress-related intestinal dysfunction is: (1) impaired small intestinal transit and motility, and (2) increased large intestinal transit and, commonly, diarrhea. The etiology of stress-induced intestinal dysfunction is completely unresolved, and the lack of an appropriate animal model has hindered studies of causality. We compared a number of stressors and their resultant effects on intestinal transit, a measure of the propulsive motor activity of the gut, in the rat. We found that the response of the intestine to stress, and the neural systems activated by stress, were dependent on the type and duration of stress, as well as the animal strain, and gender. We developed a model, acute wrapping restraint stress, to fully characterize the effects of stress on intestinal transit. Wrap restraint stress is a nonulcerogenic model in which rats are subjected to acute restraint by wrapping them in a harness of paper tape to restrict, but not prevent movement of the upper body and forelimbs. Transit was evaluated by the geometric center method, in which a radiomarker (⁵¹Cr) is instilled directly into the proximal duodenum and proximal colon via a surgically placed intestinal cannula, in fasted, adult female Sprague Dawley rats (150-200g). Subjecting animals to 35 min. of wrap restraint stress resulted in (1) inhibition of small intestinal transit, and (2) increased large intestinal transit and increased fecal output. The effects of stress on intestinal transit in rats resembled symptoms associated with stress in humans, suggesting that wrap restraint stress may be suitable as a model of stress-induced intestinal dysfunction. We found a close correlation between stress-induced intestinal dysfunction and stress-activation of endocrine systems. Stress-induced changes in intestinal function was strongly influenced by circadian variations in endocrine levels, suggesting that stress-induced intestinal dysfunction may be hormonally mediated. However, neither pituitary nor adrenal factors mediated the effects of stress on the gut. To evaluate the role of corticotropin-releasing factor (CRF), the major hypothalamic factor released in response to stress, in stress-induced intestinal dysfunction, we studied the effects of exogenous CRF on intestinal transit. CRF resulted in (1) a potent, dose-dependent inhibition of small intestinal transit, (2) a dose-dependent increase in large intestinal transit, and (3) increased fecal excretion. The effects of exogenously administered CRF closely paralleled the effects of stress on intestinal transit and on ACTH secretion in the rat. Blockade of CRF receptors by means of an antagonist, α helical CRF (9-41), prevented the effects of stress on colonic transit and fecal excretion. These data strongly suggest that endogenous CRF may mediate the effects of wrap restraint stress on intestinal motor activity and coordination in the rat.