Crohn's disease and the intestine: what happens

The small intestine absorbs nutrients, while the large intestine removes water and stores stool. Crohn's disease may involve either area, and inflamed tissue can make digestion uncomfortable or alter stool consistency. Repeated inflammation may also cause narrowing, which can make food and digestive contents harder to pass.

The location of symptoms does not reliably identify the affected bowel section. Crohn's Disease, Abdominal Pain and Diarrhoea provide useful background, but a clinician must assess the whole pattern.

Book a GP Consultation for persistent loose stools, recurring cramps, urgency, unexplained tiredness, reduced appetite or weight change. Write down stool frequency and appearance, pain location, food tolerance, medicines and any blood or fever.

A Blood Test can help check for anaemia, inflammation or nutritional concerns. Your clinician may use this information with examination and other tests. Avoid making major diet changes without advice, especially if appetite or weight is already affected.

Seek urgent care for severe cramping or constant pain, repeated vomiting, a swollen abdomen, inability to pass stool or gas, heavy bleeding, fainting or dehydration. Prompt review is also needed if symptoms worsen quickly or you become unusually weak.

Ask which part of the intestine may be involved, whether nutrition needs checking, how narrowing would be recognised, and which changes should trigger urgent care.