Ulcerative colitis is an inflammatory bowel disease that causes long-lasting inflammation and ulcers in the digestive tract. It affects the innermost lining of the large intestine and rectum. There are several types classified by the parts of the colon affected. Symptoms include diarrhea with blood or pus, abdominal pain, anemia, weight loss, nausea and fever. Complications can include severe bleeding, colon perforation, dehydration and in rare cases liver disease or colon cancer. Diagnosis involves physical exams, tests, colonoscopy, biopsy and imaging. Treatment focuses on diet, nutrition, medications like aminosalicylates, corticosteroids, antibiotics and surgery in severe cases.