Adults exposed to childhood physical or sexual abuse at risk for ulcerative colitis

Adults who were exposed to childhood physical or sexual abuse were approximately twice as likely to have ulcerative colitis, according to a new nationally representative study from four researchers at the University of Toronto.

"We found that one-quarter of adults with ulcerative colitis reported they had been physically abused during their childhood, compared to one in 10 of those without inflammatory bowel disease," said the study's lead author, Professor Esme Fuller-Thomson, who holds the Sandra Rotman Endowed Chair at University of Toronto's Factor-Inwentash Faculty of Social Work. "Similarly, the prevalence of childhood sexual abuse among those with ulcerative colitis was one in five versus one in 17 among those without the disease."

Investigators examined a representative sample of 21,852 community-dwelling Canadians aged 18 and over from the 2012 Canadian Community Health Survey - Mental Health.

"The odds of ulcerative colitis were more than two times higher for those who reported that an adult had at least once kicked, bit, punched, choked, burned or physically attacked them before the age of 16," said Joanne Sulman, study co-author and adjunct lecturer at U of T. This is in comparison to those who had not been physically mistreated.

"Occurrences of ulcerative colitis were also more than twice as high in individuals who reported that during their childhood an adult had forced them or attempted to force them into any unwanted sexual activity, by threatening them, holding them down or hurting them, in comparison to those who had not been sexually abused," said Sulman. "These strong associations remained even after we took into account sociodemographic characteristics, mental health conditions and health behaviours."

The study was published online in the journal Inflammatory Bowel Diseases.

"In contrast to the strong association between childhood maltreatment and ulcerative colitis, we found no association between either type of abuse and Crohn's disease," said Keri West, a master's student at U of T and study co-author. "This was very surprising because Crohn's disease and ulcerative colitis are two forms of inflammatory bowel disease and we expected that similar links would be apparent for the two disorders," We do not know why these differences exist but it's possible that epigenetics plays a role."

Both ulcerative colitis and Crohn's disease are debilitating immune-mediated chronic inflammatory disorders of the gastrointestinal tract. In North America, Crohn's disease affects 319 of every 100,000 people, while ulcerative colitis affects 249 out of 100,000 people.

"This research was based on a cross-sectional survey and therefore we cannot determine a cause and effect relationship, said co-author Stephanie Baird. "However, with such a high proportion of subjects with ulcerative colitis reporting childhood maltreatment, future research is clearing warranted."