Ola Olén

Ola Olén is a senior consultant at the Department of pediatric
gastroenterology and nutrition at Sachs’ children and youth hospital.

Olén is also an associate professor (docent in Swedish), group leader, and adjunct senior lecturer (lektor in Swedish) at the Clinical Epidemiology Division at the Department of Medicine Solna, Karolinska Institutet.

MY RESEARCH
The aim of my research is to improve healthcare and ultimately quality of
life for patients suffering from diseases such as inflammatory bowel disease
(IBD) or functional gastrointestinal disorders such as irritable bowel
syndrome (IBS).

*IBD*
As a pediatric gastroenterologist, most of my clinical time is devoted to
patients with IBD. They are sometimes severely ill and require advanced
treatment. I am *PI* for a large register-based linkage including all IBD
patients in Sweden and matched controls. My IBD research is conducted in
national and international collaboration and is based on clinical data in
national health registers and local registers or biobanks.

Important research questions that we explore are for instance: Why do some people get IBD? What is the
prognosis for different patient groups with IBD (and especially for patients with childhood onset)? Different treatments for IBD – are they safe? And
are they cost effective?

I am a member of the steering committee for the national quality register for IBD care (www.swibreg.se), the steering group for the Swedish guidelines in pediatric IBD, and of the Pediatric IBD Porto group of ESPGHAN (European Society for Paediatric Gastroenterology, Hepatology, and Nutrition).

*IBS*
Irritable bowel syndrome (IBS) and other types of functional abdominal pain disorders are very common: Approximately 3% of all visits to the general
practitioner, 10% of visits to general pediatricians and 20% of visits to a pediatric gastroenterology unit.

It is well known that cognitive behavior therapy and hypnotherapy are effective for children and adolescents with IBS, but access to trained therapists is very limited. In randomized clinical trials we test if it is possible to treat children and adolescents with IBS or functional abdominal pain via internet, thereby increasing accessibility to evidence-based treatments for these large patient groups.

I am also trying to understand why so many children suffer from IBS by studying risk factors for disease in birth cohorts and national health registers. In these data sources we are studying the effects of genetics, perinatal risk factors, lifestyle, co-morbidity, gut flora, and use of antibiotics.

SELECTED REFERENCES
*Olén O*, Erichsen R, Sachs MC, Pedersen L, Halfvarson J, Askling J, Ekbom
A, Toft-Sørensen H, Ludvugsson JF. Colorectal cancer in ulcerative colitis:
a Scandinavian population-based cohort study. *Lancet*. 2020

*Olén O*, Askling J, Sachs MC, Frumento P, Neovius M, Smedby KE, Ekbom A,
Malmborg P, Ludvigsson JF.
Childhood onset inflammatory bowel disease and risk of cancer: a Swedish
nationwide cohort study 1964-2014. *BMJ* 2017

*Olén O*, Askling J, Sachs MC, Frumento P, Neovius M, Smedby KE, Ekbom A,
Malmborg P, Ludvigsson JF.
Increased Mortality of Patients with Childhood-onset Inflammatory Bowel
Diseases, Compared With the General Population. *Gastroenterology* 2018

Everhov ÅH, Halfvarson J, Myrelid P, Sachs MC, Nordenvall C, Söderling J,
Ekbom A, Neovius M, Ludvigsson JF, Askling J, *Olén O*.
Incidence and Treatment of Patients Diagnosed With Inflammatory Bowel
Diseases at 60 Years or Older in Sweden. *Gastroenterology* 2018

Bonnert M, *Olén O*, Lalouni M, Benninga MA, Bottai M, Engelbrektsson J,
Hedman E, Lenhard F, Melin B, Simrén M, Vigerland S, Serlachius E, Ljótsson
B. Internet-Delivered Cognitive Behavior Therapy for Adolescents With
Irritable Bowel Syndrome: A Randomized Controlled Trial. *Am J
Gastroenterol*. 2017

Lalouni M, Ljótsson B, Bonnert M, Ssegonja R, Benninga M, Bjureberg J,
Högström J, Sahlin H, Simrén M, Feldman I, Hedman-Lagerlöf E, Serlachius
E, *Olén O*. Clinical and Cost Effectiveness of Online Cognitive
Behavioral Therapy in Children with Functional Abdominal Pain
Disorders. *Clin Gastroenterol Hepatol*. 2018

Dr Olén served as the director of studies 2009-2013 for the widely acclaimed Research school in epidemiology for clinicians at the Karolinska
Instituet. He has been director of a national course in pediatric gastroenterology, hepatology, and nutrition, funded by the National Board of
Health and Welfare 2013-2017. Dr Olén is a valued teacher and often engaged as a lecturer regarding inflammatory bowel disease, irritable bowel syndrome, and epidemiology.

Former PhD students: Bonnert M, Uusijärvi A, Lalouni M, Granlund J,
Schollin-Ask L, Forss A, Mouratidou N, Mahmood M
Current PhD students: Thulin H, Sjölund J, Jossan N,

Former Postodocs: Arnell H, Malmborg P, Everhov ÅH
Current Postdocs: Bröms G, Eriksson C, Rolandsdotter H, Forss A