Types of Crohn's disease

Ileal Crohn's affects the last part of the small intestine and may cause abdominal pain, reduced appetite, or difficulty absorbing nutrients. Colonic Crohn's affects the large bowel and may bring diarrhoea, urgency, or rectal bleeding. Ileocolitis involves both regions. Gastroduodenal disease affects the stomach or first part of the small intestine and can cause nausea, upper abdominal discomfort, or early fullness. Jejunoileitis affects a longer section of the small intestine. Doctors may also describe stricturing disease, where inflammation narrows the bowel, or penetrating disease, where inflammation forms an abnormal tunnel or collection.

These labels describe location and behaviour; they do not predict exactly how symptoms will feel or how treatment will progress.

Arrange a GP consultation or specialist review for ongoing diarrhoea, abdominal pain, weight change, blood in stool, or repeated fatigue. Keep a simple record of bowel frequency, pain location, food triggers, temperature, and medicines. A blood test can look for anaemia or inflammation, but diagnosis may also require stool tests, scans, or an examination of the bowel. Do not stop prescribed treatment without advice.

Seek urgent help for severe or worsening abdominal pain, a swollen abdomen with vomiting, inability to keep fluids down, heavy rectal bleeding, black stools, fainting, or confusion. These symptoms can signal obstruction, significant bleeding, or severe dehydration and need prompt assessment.

Ask which bowel areas are involved, whether inflammation is narrowing or penetrating the bowel, which tests are planned, and how to recognise a flare or treatment side effect.