Ulcerative colitis shifts between two states: flares and remission. A flare is a time when symptoms return or get worse. Remission is a time when symptoms disappear — and it can last for weeks or years. The goal of treatment is to keep the disease in remission long term. During a flare, common symptoms include diarrhea, blood or pus in the stool, belly cramps, and an urgent need to use the bathroom. You may also feel a constant urge to have a bowel movement even when your bowel is empty — this feeling is called tenesmus. When a flare is more severe or affects more of the large intestine, you may also feel tired, feverish, or nauseous, or lose weight. A very severe flare — called fulminant — can cause more than 10 bloody bowel movements a day, often with fever and rapid heart rate. This is a medical emergency. Go to the emergency room right away if you have these signs. Talk to your care team about how to recognize a flare and when to seek urgent care.