Faecal calprotectin (FC) is a commonly used diagnostic test which is raised in people who have inflammation present in their gastrointestinal tract. It is therefore used for differentiating between irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD), two conditions which often have overlapping presenting symptoms. If IBD is suspected people will often need invasive, unpleasant investigations such as colonoscopies which also carry a degree of risk. A normal FC makes a diagnosis of IBD unlikely and can therefore help patients avoid any unnecessary investigations.
There are however still some outstanding questions about the use of faecal calprotectin. There remains limited evidence for its use in primary care and there is also still some uncertainty regarding at what level FC should be considered raised. Some studies have suggested that at present people may be undergoing unnecessary tests as a result of borderline elevated FC levels. In addition to this there is limited evidence on the effect stool consistency has on faecal calprotectin levels. This study will attempt to address the above questions. A better understanding of the FC test will allow us to use it more effectively and prevent patients undergoing unnecessary investigations.
This study is purely observational and will have no impact on participants' clinical care.