10 Surprising Facts About Ulcerative Colitis

Ulcerative colitis affects more than 700,000 Americans, a 15% increase since 2011. Some researchers believe the Western diet and sedentary lifestyle are partly to blame. While it can hit any age group, “it usually starts in teenagers or young adults,” says gastroenterologist Stephen B. Hanauer, M.D., medical director of the Digestive Health Center at Northwestern Medicine. The majority of UC patients are diagnosed before the age of 35, according to the Crohn’s and Colitis Foundation of America (CCFA). It’s also estimated that 15% to 20% of Americans living with UC are children.

Here’s the hereditary component: A person inherits their risk from mom and pop. But for UC to actually manifest, “it takes a particular mix of genetic defects,” says Garrett Lawlor, M.D., associate director of the inflammatory bowel diseases program at NewYork-Presbyterian Hospital in New York City.

That means, strangely enough, that most people who have UC don’t have a family member with it. “Their parents have the genes, but don’t develop the disease,” says Dr. Lawlor. There are 160 genes associated with inflammatory bowel disease that researchers are trying to link to UC.

Your body doesn’t develop ulcerative colitis on a whim. First, you must be carrying the gene, which makes your immune system susceptible to overdrive mode. But that can only happen if it comes in contact with a specific trigger, which is different for every person. “It could be an infection or something in the environment,” says Dr. Lawlor. “We’re still not sure.”

Bacterial infections, such as E.coli, have been studied as a potential cause of UC. Though researchers haven’t found a smoking bacterium just yet, the theory is that the immune system overreacts to the invader and attacks the colon instead, leading to inflammation and ulceration.

Inflammation of the colon can actually cause an inflammatory response throughout the rest of your body, says Stephen B. Hanauer, M.D., medical director of the Digestive Health Center at Northwestern Medicine in Chicago. This includes the potential for joint swelling and pain, which usually go away once the inflammation in the gastrointestinal track eases. In fact, arthritis is one of the most common complications—up to 30% of people with UC experience it.

“The sick colon spasms, which causes frequent diarrhea,” says Dr. Hanauer. “This commonly leads to cramps and abdominal pain too.” You may feel discomfort more on your left, as one type of UC disproportionately targets the colon on that side.

Two issues build on each other to cause this: 1) Because diarrhea is one of UC’s most common symptoms—inflammation prevents the colon from absorbing water, leading to runny poop—the body struggles to adequately absorb the nutrients necessary for healthy living, says Dr. Lawlor. “Patients are sometimes dehydrated or develop a deficiency in certain vitamins and elements, especially vitamin D and iron," he adds. And 2) All this diarrhea can lead to rapid weight loss, meaning the nutrients you do get, you lose.

UC may suck, but it doesn’t lie: True to its name, ulcerative colitis is characterized by colon ulcerations, “which can cause bleeding,” says Dr. Hanauer. That’s why anemia can crop up. “Chronic blood loss from the colon can lead to iron-deficiency anemia,” says Dr. Hanauer. People with anemia lack enough red blood cells to carry oxygen throughout the body, making them feel tired and weak.

“With ulcerative colitis, the rectum cannot relax, creating the feeling of constantly needing to evacuate,” says Dr. Hanauer. This all-too-often “I gotta go now” sensation is called tenesmus, and it’s annoying because much as you try and strain, there’s often nothing (or little) left to empty from your large bowel.

“It’s common to suffer low mood or depression with ulcerative colitis,” says Dr. Lawlor. “Perhaps it’s related to the burden of the disease—impact on social life, ability to work, or even the stigma of bowel disorders that sometimes still occurs.”

Those with UC also have been found to have higher rates of depression even before a diagnosis. A study published in the Canadian Journal of Gastroenterology and Hepatology suggested that depression could be a response to an asymptomatic, undiagnosed bowel disorder, but more research is necessary to fully understand the connection.

Just as chronic inflammation can cause cancers in other organs (smokers and lung cancer; hepatitis and liver cancer; sunburn and skin cancer), uncontrolled inflammation in ulcerative colitis is associated with an increased risk of colon cancer, explains Dr. Hanauer. While only 1% to 2% of all colon cancer cases are caused by UC, it accounts for 10% to 15% of deaths in those with UC.