Patients will receive a faeces sample kit the first day they meet to MRI. The sample should be taken two days after the MRI scan and sent through the mail. The sample should contain about 5-10 g of faeces and it will be analyzed by ELISA method for calprotectin. Calprotectin is a good marker for the degree of inflammation in the intestines. [5] Analysis of each sample immediately after the reception is too costly. The samples are therefore frozen on the gastroenterology department at Herlev Hospital. When the investigators have collected about 20 samples which is expected to do within one month the samples are analyzed for calprotectin. The material are destroyed immediately after the analysis and can not be used in future research projects.