Severe ulcerative colitis symptoms: what to know

Ulcerative colitis is inflammation affecting the lining of the large bowel. A severe flare may produce repeated loose stools, visible blood or mucus, urgency, cramping and pain in the abdomen. Ongoing fluid and blood loss can leave you dizzy, thirsty, unusually tired or unable to keep up with drinking. Fever, a fast heartbeat, a swollen abdomen or worsening tenderness can signal that the bowel is under significant strain. These symptoms describe the condition’s possible presentation; they do not establish the diagnosis by themselves. Read more about [Ulcerative Colitis](/conditions/ulcerative-colitis/), [Abdominal Pain](/symptoms/abdominal-pain/) and [Diarrhoea](/symptoms/diarrhoea/).

Contact a doctor promptly if symptoms are escalating, blood is increasing, or drinking is difficult. Keep taking prescribed medicines unless a clinician tells you otherwise, and record stool frequency, bleeding, pain, temperature, fluid intake and medicines taken. Small, frequent sips may be easier than large drinks while you arrange care. Avoid using anti-diarrhoeal medicines or anti-inflammatory painkillers without medical advice, because they may be unsuitable during a flare. A [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can help arrange examination, blood tests or hospital assessment.

Seek emergency help for severe or rapidly worsening abdominal pain, a swollen or rigid abdomen, fainting, confusion, heavy bleeding, repeated vomiting, inability to drink, very little urine, or marked weakness. Urgent assessment is also needed when fever accompanies a severe flare or you feel your heart racing at rest. Do not drive yourself if you are faint or confused. Colorectal screening is a separate planned service; ask a clinician whether [Colorectal Cancer Screening](/treatments/diagnostics-and-screening/colorectal-cancer-screening/) is appropriate for you.

Ask: Could this be a severe flare or another bowel problem? How should I monitor bleeding and hydration? Which medicines should I continue today? Do I need blood or stool tests, intravenous fluids, or hospital review? What warning signs should prompt emergency help?