Colitis
التهاب القولون
Inflammation of the inner lining of the colon, which can be caused by infection, reduced blood flow, or — in ulcerative colitis, a form of inflammatory bowel disease — an overactive immune response. It's distinct from irritable bowel syndrome (IBS): colitis involves visible inflammation and tissue damage, while IBS is a functional disorder without structural damage. Treatment depends heavily on the specific cause and can include medication to control inflammation or address the underlying trigger.
This information is for general awareness only and does not replace professional medical advice. Consult a doctor for diagnosis and treatment.
Quick answer
Colitis is inflammation of the lining of the colon (large bowel). It can be caused by infection, reduced blood flow, medicines, or an over-active immune response — as in ulcerative colitis, a form of inflammatory bowel disease (IBD).
Common symptoms are diarrhoea (often with blood or mucus), abdominal pain and cramping, urgency to open the bowels, and sometimes tiredness and weight loss.
Diagnosis uses stool and blood tests and a colonoscopy with biopsies. Treatment depends on the cause: infections and medicine-related colitis are treated differently from ulcerative colitis, which needs long-term anti-inflammatory treatment and specialist follow-up.
Symptoms
Diarrhoea
Often with blood or mucus.
Abdominal pain and cramping
Urgent need to open the bowels
Sometimes with difficulty controlling it.
Blood in the stool
Tiredness
Weight loss and reduced appetite
Fever during flare-ups
Symptoms outside the gut
Joint pain, eye or skin problems occur in some people with IBD.
Causes and risk factors
Causes
- Ulcerative colitis — An immune-mediated inflammatory bowel disease; the exact cause is not fully understood.
- Infection — Bacteria, viruses or parasites, including infection after antibiotic use (C. difficile).
- Ischaemic colitis — Reduced blood flow to part of the colon.
- Medicines — Some drugs, including certain painkillers and antibiotics, can inflame the colon.
- Other inflammatory causes — Such as microscopic colitis or radiation-related colitis.
Risk factors
- Family history of inflammatory bowel disease
- Age — ulcerative colitis often starts between the teens and thirties, though it can begin later
- Recent antibiotic use or hospitalisation — Risk factors for infectious colitis.
- Older age and vascular disease — Risk factors for ischaemic colitis.
- Use of certain medicines
How is it diagnosed?
Because colitis has many causes, finding the cause guides treatment.
History and examination
Symptoms, medicines, recent infection, travel and family history.
Stool tests
To look for infection, and for markers of inflammation.
Blood tests
For inflammation, anaemia, and nutrition.
Colonoscopy with biopsies
Allows direct viewing of the lining and confirms the type of colitis.
Imaging
Used in some situations, particularly severe flare-ups or suspected complications.
Treatment
Treatment depends on the cause and severity. It is directed by a doctor, often a gastroenterologist.
Treating infection
Fluids, and antibiotics only when the specific cause requires them.
Anti-inflammatory medicines for ulcerative colitis
Options include aminosalicylates, corticosteroids for flare-ups, immune-modulating and biological therapies.
Reviewing triggering medicines
Stopping or changing a medicine that caused colitis, when advised.
Nutrition and supportive care
Hydration, and correcting anaemia or nutritional deficiencies.
Surgery
Considered for severe disease, complications, or when medicines fail.
Long-term follow-up
Regular monitoring, including surveillance colonoscopy in long-standing ulcerative colitis.
Do not stop prescribed medicines during a flare-up or when well without medical advice.
When should you see a doctor?
Arrange a medical assessment if
- Persistent diarrhoea, especially with blood or mucus
- Symptoms lasting more than a couple of weeks
- Weight loss or tiredness with bowel symptoms
- Night-time diarrhoea
- A family history of IBD or bowel cancer
Seek urgent care if
- Severe abdominal pain or a swollen abdomen
- Heavy bleeding, or black or bloody stools with dizziness
- High fever, fast heart rate or signs of dehydration
- Persistent vomiting
Prevention
Take antibiotics only when prescribed
To reduce the risk of antibiotic-associated colitis.
Practise food safety and hand hygiene
To reduce infectious colitis.
Don't smoke
Smoking affects many bowel conditions.
Keep follow-up appointments
If you have ulcerative colitis, to prevent flare-ups and detect complications early.
Frequently asked questions
What is colitis?
Inflammation of the colon's inner lining, which can have several causes.
What is the difference between colitis and IBS?
Colitis involves visible inflammation and tissue damage in the bowel. IBS is a functional disorder without such damage.
Is ulcerative colitis curable?
It is a long-term condition managed with medicines to keep it in remission; surgery to remove the colon can be curative for the bowel disease in selected patients.
What are the symptoms of colitis?
Diarrhoea, often with blood or mucus, abdominal pain, urgency, tiredness and sometimes weight loss.
How is colitis diagnosed?
With stool and blood tests and usually a colonoscopy with biopsies.
Can diet cure colitis?
Diet doesn't cure it, but nutrition support and avoiding personal trigger foods can help symptoms. Medicines remain the mainstay for inflammatory types.
Related specialties
Related services & tests
Related conditions
Related articles
Looking for a doctor?
Find a specialist who treats this condition, and compare profiles before you book.
Medical sources
This page summarizes general information from the sources below.