Crohn's disease
Can affect any part of the digestive system, from the mouth to the anus. Inflammation can extend through all layers of the bowel wall and may appear in separate patches.
Crohn's disease and ulcerative colitis
Understanding IBD.
Inflammatory bowel disease affects more than the bowel. It can shape energy, confidence, work, relationships and everyday plans.
The condition
What inflammatory bowel disease means.
IBD covers lifelong conditions that inflame the digestive system. The main forms are Crohn's disease and ulcerative colitis.
IBD is not irritable bowel syndrome (IBS), although symptoms can overlap. Its cause is unclear; the immune system, genes and environment all appear involved.
Symptoms can come and go. Active periods are called flare-ups; quieter periods are called remission. Someone may look well while managing pain, fatigue, urgency or toilet anxiety.
The two main forms
How Crohn's disease and ulcerative colitis differ.
Ulcerative colitis
Affects the large bowel — the colon and rectum. Inflammation usually starts in the rectum, is continuous and affects the inner lining of the bowel.
Day-to-day reality
Common symptoms and day-to-day effects.
Symptoms vary by person and over time. They can be unpredictable, visible or completely hidden.
- Urgency and diarrhoeaNeeding a toilet quickly or frequently can make travel and unfamiliar places difficult.
- Pain and bleedingAbdominal pain, cramping, blood or mucus in stools can occur during active disease.
- FatiguePersistent exhaustion can remain even after rest and may continue when bowel symptoms are quieter.
- Weight and appetite changesInflammation and reduced food intake can lead to unplanned weight loss or nutritional problems.
- Effects beyond the bowelSome people experience problems affecting joints, eyes, skin, bones, liver or mental wellbeing.
- UncertaintyPlanning around symptoms, toilets, treatment and possible flare-ups can reduce confidence and social connection.
A growing global burden
Global prevalence is increasing.
IBD was historically most common in Europe, North America, Australia and New Zealand. Rates are now rising across Asia, Latin America and parts of Africa.
More than 500,000 people in the UK — around 1 in 123 — live with Crohn's, colitis or unclassified IBD.
Evidence: Nature global epidemiology study, 2025 · Crohn's & Colitis UK prevalence research
Treatment and support
Treatment and clinical support.
Care aims to control inflammation, ease symptoms and prevent complications. Treatment may include medicines, nutritional support or surgery.
Treatment decisions belong with an IBD team. FUS does not provide medical advice or treatment; its planned programme complements established support.
Why Freedom Under Sail
How the pilot will account for IBD.
IBD symptoms can make travel, social participation and unfamiliar activities difficult.
The planned pilot includes small groups, a private toilet, rest options, confidential pre-booking discussions and clear operating limits. It is a wellbeing activity, not medical treatment.
Read the participant guideTrusted information
Sources and further support.
NHS: Inflammatory bowel diseaseOverview, symptoms, treatment and when to seek urgent help.
Crohn's & Colitis UK: All about Crohn's and ColitisDetailed UK information about the conditions and who they affect.
Crohn's & Colitis UK: SymptomsInformation about bowel symptoms, fatigue and effects elsewhere in the body.
Crohn's & Colitis UK: TreatmentsAn introduction to treatment choices and working with an IBD team.
Medical note: This page provides general awareness information, not diagnosis or personal medical advice. Speak to a GP or your IBD team about symptoms or treatment. For severe pain, heavy or non-stop rectal bleeding, or vomiting blood, follow the NHS urgent-care guidance above.