The most common signs and symptoms of ulcerative colitis (UC) include:

• Diarrhea. Loose, watery stool. Inflammation causes the large intestine to empty frequently, resulting in diarrhea. The farther up the large intestine the inflammation occurs, the more loose and watery the stool and the more frequent the bowel movements. Dehydration may occur if too much water and salt exits the body with diarrhea. Because loose, watery stool is more difficult to retain in the rectum, fecal incontinence may also occur.
  
  
• Blood or mucus in the stool (including bloody diarrhea). Sores (ulcers) in the lining of the large intestine can bleed and produce pus, resulting in the presence of blood or mucus in stool. Anemia may result if too much blood is lost with stool, which may cause fatigue.
  
  
• Abdominal pain. Pain felt in the abdomen may be the result of inflamed tissue lining in the large intestine.

Other signs and symptoms may include:

• Cramping. Muscle contractions that normally occur to move stool through the large intestine may intensify in patients with UC and cause cramping.
  
  
• Urgency to have a bowel movement. Patients with UC may experience sudden and urgent sensations to defecate. When patients are unable to make it to a restroom quickly enough to expel stool, fecal incontinence may occur.
  
  
• Tenesmus. The inability to pass stool, despite an urge to do so. This may occur in patients with UC where inflammation is confined to the rectum, the last part of the large intestine, just before the anus.
  
  
• Unexplained weight loss. This may occur as a result of the loss of body fluids due to diarrhea and loss of nutrients due to malabsorption. Patients with UC experience malabsorption less often than patients with Crohn’s disease (the other major type of inflammatory bowel disease [IBD]) since UC does not affect the small intestine, where most nutrient absorption occurs.
  
  
• Fever. Patients with moderate or severe UC may experience a rise in body temperature.
  
  
• Nausea and vomiting. Chronic inflammation and irritation of the large intestine due to UC may cause a loss of appetite, feelings of queasiness and vomiting.

Symptoms of UC may range from mild to severe, with half of all patients experiencing mild symptoms. Symptom severity is usually stable – only rarely do patients with mild symptoms later develop more severe signs and symptoms. Examples include:

Anyone who experiences a persistent change in bowel movements, fever that lasts more than a couple of days, or abdominal pain and bloody stool should seek medical attention immediately.