Crohn's disease pathophysiology explained

The digestive tract normally balances immune protection with tolerance of food and helpful microbes. In Crohn's disease, this balance becomes disrupted in susceptible people. Inflammation can appear in sections of the digestive tract and may reach deeper bowel layers. Healing and flare-ups can alternate, so symptoms may change over time.

Swelling and irritation can cause abdominal pain and diarrhoea. Ongoing inflammation may interfere with appetite, digestion, or nutrient absorption. Deeper inflammation can lead to narrowing, while an ulcer can cause bleeding. Abdominal pain is a common presentation of Crohn's disease, but abdominal pain is not proof that a person has Crohn's disease.

Record symptom patterns, bowel changes, fever, fatigue, and possible triggers before your appointment. A GP may assess your abdomen, review medicines and family history, and arrange blood testing or referral. Treatment aims to calm inflammation, support nutrition, and prevent complications; the choice depends on affected areas, severity, previous treatment, and other health needs. Follow the prescribed plan and discuss smoking, supplements, or dietary restrictions before making major changes.

Contact a clinician when diarrhoea persists, pain keeps returning, blood appears in the stool, or fatigue and appetite loss interfere with daily life. Seek urgent care if pain becomes severe, vomiting prevents fluids, the abdomen becomes swollen, or you feel faint or confused. A fever with worsening bowel symptoms also needs prompt assessment. Urgency is based on the warning signs, not on whether a symptom is commonly linked with Crohn's disease.

Ask what part of the digestive tract may be inflamed, how disease activity will be checked, and whether a Blood Test is appropriate. Ask how to recognise a flare, whether current medicines can cause bowel symptoms, and when to arrange a GP Consultation.