Ulcerative colitis is a chronic disease of the large intestine, also known as the colon, in which the lining of the colon becomes inflamed and develops tiny open sores or ulcers.

The exact cause of Ulcerative Colitis is not completely understood, but it’s believed to be a result of a combination of factors:

1. Immune System: One theory is that the body’s immune system reacts inappropriately to normal bacteria in the digestive tract, causing inflammation and ulcers. It’s also possible that other types of bacteria or viruses may trigger the disease.

2. Genetics: Ulcerative colitis tends to run in families, suggesting that genes may play a role. However, not everyone with these genetic factors develops the disease.

3. Environmental Factors: Certain elements in the environment may also contribute to the development of Ulcerative Colitis, including diet, pollution, and the use of certain medications.

4. Smoking: Unlike Crohn’s disease, smoking seems to reduce the risk of Ulcerative Colitis. However, because of the many harmful effects of smoking, it’s not usually considered a protective factor against the disease.

It’s important to note that while these factors can increase the risk of developing Ulcerative Colitis, they don’t necessarily cause the disease.

Many people with one or more of these risk factors never develop Ulcerative Colitis, and others develop the disease without any of these risk factors.

This condition is the result of an abnormal response by your body’s immune system.