Abstract
There is limited research concerning food intolerance and an absence of services for patients who believe that they have a food intolerance. This thesis aimed to explore food intolerance in a Primary Care setting (four GP surgeries) through four related studies. The first study used a survey method to assess the prevalence of perceived food intolerance in a community sample. The second study involved the development and exploratory evaluation of four nurse-led food intolerance clinics being piloted in the Primary Care setting. The third and fourth studies used in-depth interviews (n=10) to explore patients' experiences of food intolerance symptoms and the processes of symptom change in patients who had attended the clinic and experienced symptom improvement. The initial cross-sectional survey revealed that, in a community sample (n = 2,384, 37% response rate), the prevalence of perceived food allergy was 17.7% and of food intolerance was 33.5%. Respondents reported high levels of food avoidance, but low levels of help-seeking and high levels of interest in a food intolerance clinic. The evaluation of the food intolerance clinics in the GP surgeries revealed significant improvements in symptoms, health status and mood following a two week Healthy Eating diet (n =150), and further improvements in symptoms for individuals who continued on to a Wheat and Dairy-Free diet (n = 44). In addition, participants reported changes in illness cognitions, including increased illness coherence. The third study revealed that symptoms prior to the clinic had a significant negative impact on individuals' lives, and were associated with feelings of uncertainty, the need to find a cause and issues concerning the legitimacy of symptoms. Despite help-seeking attempts, patients were unable to identify appropriate causes or treatment for their symptoms. The qualitative analysis of patients' accounts in the fourth study identified that key mechanisms of perceived symptom change were the therapeutic alliance with the nurse, the awareness gained from food diaries and the process of identifying a culprit food. Through these mechanisms patients described gaining a sense of illness coherence and legitimacy, which was linked to increased control and a return to normality in their lives.