Ulcerative Colitis Blog

The concept that the origin of adulthood disease may be influenced by environmental factors early in life has become a topic of great interest. In utero events, pre-term birth, and low birthweight have been associated with the development of some chronic diseases later in life. In the November edition of the Inflammatory Bowel Diseases Journal, investigators from Germany performed a study to determine whether a variety of early life events may make people more likely to develop IBD. Over 1800 patients with IBD were compared with 900 healthy individuals regarding their gestational age at birth, mode of delivery (C-section vs. vaginal), birthweight, history of health problems during their mother's pregnancy, breastfeeding, and health problems in the first year of life. The researchers found that individuals with IBD were one and a half times more likely than healthy controls to have been born pre-term and have a maternal history of health problems while their mother was pregnant. Furthermore, people with IBD were twice as likely to have had a significant illness during the first year of life. No association was found between mode of delivery or history of breastfeeding and the development of IBD.

While the finding of an association between two factors does not prove a causal link, it does provide interesting fodder for thought. Pre-term birth and maternal complications during pregnancy are often a result of infections. It has been postulated that early exposure to pathogens may in some way program the immune system predisposing to inflammatory disease later in life. Pre-term birth and maternal complications may result in physiologic stress to a fetus, altering the hormonal or immunologic milieu with longstanding consequences. While the current research is speculative at best, it does open more avenues for possible investigation into the cause of IBD.

Barbara wrote into the blog this week regarding her diagnosis of ulcerative proctitis/colitis and queried what causes colorectal inflammation in UC:

"I had a routine colonoscopy in Sept of 2006 and all of just fine....I never had problems in that area.....in May of 2007 I was struck with a terrible intestinal virus which caused me to vomit and have diarrhea at the same time for 5 days....it was the worst illness I have ever had....when it was over I started to bleed from the rectum with my bowel movements and shortly afterwards I was given a sigmoidoscopy and it was determined through biopsies that I had UC of the rectum or Proctitis....I am still in shock with this diagnosis since I never had a problem in this area.....what could have caused this to happen to me?"

Barbara's story of feeling completely fine and even having a normal colonoscopy prior to the onset of UC is not uncommon. The onset of UC is most often abrupt and seems to occur out of the blue. Barbara's question about why this happened to her is one of the most frequently asked questions by patients. While an exact cause for UC is not known, current theory suggests that it is likely due to a combination of genetics and environmental triggers. When a genetically predisposed individual comes in contact with a causal environmental agent, he/she may develop an inflammatory state that results in colitis. There is a lot of ongoing research regarding the genetics of IBD and what the potential environmental triggers could be.

At the present time, the search for genes suspected to cause IBD has been more fruitful for Crohn's disease than UC. Advances in new genetic and molecular techniques, however, may help in the identification of genetic markers in UC.

Much research has focused on environmental agents that may be associated with the onset or exacerbation of IBD. Some postulated risk factors for IBD include:

1) Cigarette smoking - protective factor for UC; flares often occur after smoking cessation
2) Prior appendectomy - protective factor for UC, risk factor for Crohn's
3) Antibiotics - may alter bowel flora
4) Oral contraceptives - weak association if any
5) High fat or sugar diet - no conclusive evidence for dietary causes
6) Lack of breastfeeding as an infant
7) Infections (both GI and otherwise)
8) Vaccinations - no conclusive evidence vaccinations cause IBD
9) Alterations in bowel bacteria

Barbara relates that she had a significant gastrointestinal infection which preceded the onset of her UC. Many patients describe such an event which seems to incite an inflammatory cascade that results in UC. As discussed in a previous blog, patients with UC have a predilection for GI infections cause by a bug called C. diff. Thus, in Barbara's case it may be that she possesses a genetic predisposition to IBD and her gastrointestinal infection was the inciting event for her UC.

For more information on the genetics and causes of IBD, please see our blogs from July 17 and 19, 2007 in the archives.