The colon is the end of the digestive tract, and as such is part of the metabolic process—it mostly removes water from the waste left behind after the nutrients have been extracted from food by the small intestine. When it becomes inflamed, generally due to an autoimmune response in which the body’s immune system attacks healthy tissue, waste cannot properly pass out of the body. This can result in pain, bleeding or bloody stool, constipation, fatigue, and weight loss. Some forms of colitis can lead to dehydration and shock, and may even be fatal. Immediate medical attention is needed for people who have blood in the stool, ongoing diarrhea, or fever lasting more than a day or two.
The causes of colitis are not entirely clear. It’s an autoimmune disease, but researchers are still exploring what might trigger it. As with many autoimmune diseases, there appears to be a genetic component. A recent study fount that the absence of a protein called macrophage-stimulating protein receptor resulted in severe damage to the colon, signs of inflammation, and symptoms of colitis, such as weight loss.
Colitis is treated with corticosteroids and other drugs that help fight inflammation, but patients are also generally advised to modify their eating habits, adopting what are called "low-residue" diets so as to minimize the burden on the colon. That normally means avoiding dietary fiber. However, researchers have created a new type of dietary fiber that encourages the growth of important gut microflora and minimizing the effects of intestinal bowel disease. The gut microflora are benign bacteria living in the digestive tract that play a role in breaking down food to help the body metabolize it.
Another treatment being studied focuses on the role played by a cell adhesion molecule called CD146 in the development of colitis. As the name suggests, cell adhesion molecules ordinarily act as a sort of glue to help cells stay in place. CD146 is found in the inner walls of the blood vessels, in smooth muscle cells, and in the immune system and has been shown to help stop the progression of breast cancer. However, it also has a dark side—when produced in excess, CD146 is a part of inflammatory diseases such as colitis. A treatment that deactivates some of the CD146 has been shown in laboratory animals to have good potential to fight colitis.