Sudden abdominal pain, an urgent need to open the bowels, followed by blood in the stool may initially be blamed on gastroenteritis, haemorrhoids or simply "something you ate". But when the symptoms appear suddenly, particularly in an older person, another possible cause is ischaemic colitis.
Ischaemic colitis occurs when blood flow to part of the large intestine is temporarily reduced, depriving the bowel wall of oxygen and causing inflammation and injury.
Symptoms may include sudden cramping abdominal pain, urgency, diarrhoea and blood in the stool. Older age, cardiovascular disease, low blood pressure, severe dehydration and other conditions that affect blood circulation may increase the risk.
Some mild cases may improve as blood flow returns to normal, but this is not something that can be reliably assessed at home. Abdominal pain with rectal bleeding can also occur with infectious colitis, inflammatory bowel disease and other potentially serious bowel conditions.
If abdominal pain is severe or persistent, bleeding increases, or fever, dizziness or deterioration in general condition develops, prompt medical attention should be sought.
The important question is not simply why there is blood in the stool, but what has caused the bowel to become injured in the first place.
