@article {Bajor84, author = {Antal Bajor and Hans T{\"o}rnblom and Mats Rudling and Kjell-Arne Ung and Magnus Simr{\'e}n}, title = {Increased colonic bile acid exposure: a relevant factor for symptoms and treatment in IBS}, volume = {64}, number = {1}, pages = {84--92}, year = {2015}, doi = {10.1136/gutjnl-2013-305965}, publisher = {BMJ Publishing Group}, abstract = {Objective Bile acids may play a role in the pathogenesis of IBS. We investigated the potential effects of bile acids entering the colon and its role in the symptom pattern in IBS. Design We measured 75Se-labelled homocholic acid-taurine (75SeHCAT) retention, and serum levels of 7α-hydroxy-4-cholesten-3-one (C4) and fibroblast growth factor (FGF) 19 in patients with IBS (n=141) and control subjects (75SeHCAT n=29; C4 and FGF19 n=435). In patients with IBS stool frequency and form, as well as GI symptom severity were registered, and in a proportion of patients colonic transit time and rectal sensitivity were measured (n=66). An 8-week open-label treatment with colestipol was offered to patients with 75SeHCAT \<20\%, and the effect of treatment was evaluated with IBS severity scoring system and adequate relief of IBS symptoms. Results Compared with controls, patients with IBS had lower 75SeHCAT values (p=0.005), higher C4c levels (C4 corrected for cholesterol) (p\<0.001), but similar FGF19 levels. Abnormal 75SeHCAT retention (\<10\%) was seen in 18\% of patients, whereas 23\% had elevated C4c levels. Patients with IBS with 75SeHCAT retention \<10\% had more frequent stools, accelerated colonic transit time, rectal hyposensitivity, a higher body mass index, higher C4c and lower FGF19 levels. Colestipol treatment improved IBS symptoms (IBS severity scoring system 220{\textpm}109 vs 277{\textpm}106; p\<0.01), and 15/27 patients fulfilled criteria for treatment response (adequate relief >=50\% of weeks 5{\textendash}8). Conclusions Increased colonic bile acid exposure influences bowel habit and colonic transit time in patients with IBS. A high response rate to open label treatment with colestipol supports this, but placebo-controlled studies are warranted.}, issn = {0017-5749}, URL = {https://gut.bmj.com/content/64/1/84}, eprint = {https://gut.bmj.com/content/64/1/84.full.pdf}, journal = {Gut} }