Colitis is an inflammation of the inner lining of the colon, which is part of the digestive system. It can cause symptoms such as abdominal pain, diarrhea, and rectal bleeding. There are several types of colitis, including ulcerative colitis and infectious colitis, each with different causes and treatments. The condition can be triggered by infections, inflammatory bowel diseases, or certain medications. Diagnosis typically involves medical history, physical exams, and tests like colonoscopy. Treatment options may include medications to reduce inflammation, dietary changes, and in severe cases, surgery to remove affected sections of the colon.