Colitis is an inflammation of the large intestine, also known as the colon. This condition can primarily be triggered by infectious agents such as viruses, harmful bacteria (e.g., Campylobacter, Shigella, E. Coli, Yersinia, Salmonella), or parasites.

Other potential causes include bacterial food poisoning, Crohn's disease, allergic reactions, reduced blood flow to the large intestine, and radiation therapy.

While dietary habits and stress do not directly cause colitis, they can trigger or exacerbate existing symptoms.