This study was designed to identify the processes which underlie pain in symptomatic diverticular disease (SDD). Our hypothesis was that a spectrum of both peripheral and central pathologies were involved, with those that had a more peripheral problem having abdominal symptoms only while those with multiple symptoms throughout the body, having an altered central pain processing. The first study examining the brain response to cutaneous pain using functional magnetic resonance imaging (fMRI) has supported this hypothesis. Although a statistically significant difference in sensory pain threshold was not demonstrated between the groups, fMRI imaging has shown greater emotional processing during pain and reduced anticipatory inhibitory responses in the high somatising symptomatic diverticular disease (HSDD) groups. However this is not as clear cut as we had anticipated which may be due to subject selection and demonstrate a spectrum of mixed peripheral and central changes as well as those with only peripheral or central components. In the second part we performed a randomized placebo controlled study of mesalazine 3gm versus placebo. Mesalazine significantly reduced expression of many genes associated with inflammation in SDD patients. A reduction in the median number of hours of pain per week was seen. The study was not designed to allow intention to treat analysis but has shown promising results which will need to be consolidated with future large scale studies. Both these studies support a tailored approach to SDD patient treatment based on the underlying pain process which can be both central and peripheral. The Patient health questionnaire 12(PHQ12) may be one simple measure of doing this, but again needs to be confirmed with further larger studies.