Patient information · Gastroenterology
Crohn's disease and ulcerative colitis
not IBS, and one blood-and-stool test tells them apart
Inflammatory bowel disease is genuine inflammation and ulceration of the gut, distinct from irritable bowel syndrome despite the overlapping symptoms. It causes visible damage, responds to specific treatment, and delay in diagnosis carries a real cost — which is why the test that distinguishes the two is worth doing early.
Seek urgent assessment if you have
- severe abdominal pain with a distended, tender abdomen and fever
- more than six bloody stools a day, with a racing heart or feeling faint
- persistent vomiting and not passing wind — possible obstruction
- heavy rectal bleeding, or dizziness on standing
- a flare not responding to treatment after a few days
- new severe pain around the anus with swelling — possible abscess or fistula
A severe colitis flare can progress to toxic megacolon, which is life-threatening. Bloody diarrhoea with fever and a fast heart rate needs same-day hospital assessment. In an emergency call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
Symptoms that point away from IBS
- Blood or mucus in the stool
- Diarrhoea waking you at night — IBS characteristically does not
- Unintentional weight loss, fever, or persistent fatigue
- Mouth ulcers, joint pains, red painful eyes or skin lesions — inflammation outside the gut
- Anaemia, or raised inflammatory markers
- Perianal problems — fissures, abscesses, fistulas, particularly in Crohn's
- a family history of inflammatory bowel disease
Faecal calprotectin is the test
Calprotectin is a protein released by inflammatory cells into the stool. It is high in inflammatory bowel disease and normal in IBS, and it is a simple sample you provide at home. It is the single most useful test for distinguishing the two and avoiding an unnecessary colonoscopy — or prompting a necessary one. Anyone told they have IBS without ever having had a calprotectin and coeliac screen has not been fully assessed.
The two conditions
- Ulcerative colitis — continuous inflammation of the lining, always involving the rectum and extending upwards. Bloody diarrhoea and urgency are typical.
- Crohn's disease — can affect anywhere from mouth to anus, in patches, through the full thickness of the wall. More often causes pain, weight loss and perianal disease, and can lead to strictures and fistulas.
- Diagnosis is confirmed by colonoscopy with biopsies, plus imaging of the small bowel in Crohn's.
Treatment
- Aminosalicylates (mesalazine) for ulcerative colitis, both to treat flares and to maintain remission. Keep taking them when well — they also reduce bowel cancer risk.
- Steroids for flares, tapered down. Not for long-term use.
- Immunosuppressants such as azathioprine or methotrexate, with regular blood monitoring.
- Biologic and small-molecule therapies, which have transformed outcomes over the last two decades.
- Surgery for complications, strictures, or disease not controlled medically.
- Exclusive enteral nutrition is first-line for children with Crohn's and effective in adults.
Living with it
Worth doing
- Take maintenance treatment even in remission — stopping is the commonest cause of flares
- Stop smoking, which markedly worsens Crohn's
- Have iron, B12, folate, vitamin D and bone density monitored
- Keep vaccinations up to date, and have them before starting immunosuppression
- Carry a RADAR key and know where toilets are — practical, and it reduces anxiety
Watch for
- NSAIDs, which can trigger flares
- Assuming every flare is the disease — infection, including C. difficile, mimics it
- Repeated steroid courses without a maintenance plan
- Skipping surveillance colonoscopies
- Antibiotics for diarrhoea without testing first
Surveillance
Long-standing extensive colitis carries an increased risk of bowel cancer, and regular surveillance colonoscopy is recommended starting around eight to ten years after diagnosis, at intervals based on your risk. This is one of the strongest arguments for staying engaged with a service even during long periods of remission.
Why come to us. The most valuable thing we do here is separate this from IBS quickly. We arrange faecal calprotectin, coeliac screening, full blood count, ferritin and inflammatory markers — the whole panel — with bloods taken in-house and results explained in one visit, usually within days. Where the results point to inflammatory bowel disease we arrange colonoscopy and gastroenterology through our CQC-registered partners promptly, rather than months of watchful waiting.
Calprotectin and the full panel, results in days
Bloods in-house, colonoscopy arranged fast. Seven days a week.
Tower Bridge Hospital London
97–99 Whitechapel Road, London E1 1DT
WhatsApp 07903 284 189
info@mhwclinic.co.uk
Open Mon–Sat, 9am–7pm (closed Sundays until September)
In an emergency
Call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
When we are closed and it is not an emergency
Call NHS 111 or visit 111.nhs.uk.