Colitis in dogs is a condition in which the lining of the large intestine becomes inflamed and irritated, causing frequent and often painful defecation, as well as other uncomfortable digestive symptoms. Common causes include dietary indiscretion, food allergies, foreign material ingestion, and parasites. Risk factors include an unbalanced diet, parasites, environmental irritants, and certain drugs. Treatment for colitis in dogs may include dietary changes, medications, and/or supplements. In some cases, surgery may be necessary. If left untreated, colitis can cause serious health complications. Therefore, it is important to seek veterinary care if your dog is exhibiting signs of colitis, such as diarrhea, vomiting, abdominal pain, loss of appetite, and general discomfort.