The incidence of inflammatory bowel disease (IBD; ulcerative colitis and Crohn's disease) in children and adolescents is rapidly increasing.
In most countries the incidence of Crohn's disease (CD) is higher than that of ulcerative colitis (UC).
Diagnosis and treatment management is the responsibility of specialist health care; the role of the primary health care is to be alert to the possibility of IBD.
CD may be associated with growth failure or delayed puberty even before significant bowel problems are manifest.
The disease may develop at any age. Childhood-onset IBD typically starts at the onset of puberty.
Epidemiology
The current incidence of IBD in children and adolescents is about 15/100 000, but the incidence figures are rising.
Clinical presentation
CD in children often starts in the colon and the symptoms resemble UC (see below).
Symptoms are usually insidious in onset.
UC is more extensive and severe in children and adolescents than in adults, and in the majority of cases the entire colon is affected. Isolated rectal inflammation is encountered only rarely.
Frequency of defecation especially in the mornings
Intermittent blood in stools
Nocturnal stools
Moreover, abdominal pain and weight loss as well as recurrent mouth ulcers or intermittent fever are seen in CD.
Some patients have intermittent joint complaints.
Clinical findings
Increased bowel sounds and slight abdominal tenderness on palpation
Pallor (in most cases)
In CD: sometimes perianal skin tags
In CD: sometimes mouth ulcers, cobblestone appearance of the oral mucosa or erythema of the lips or gums
Weight loss, a decrease in growth velocity or delayed puberty are common in CD.
Diagnosis and investigations
If there is a strong suspicion of IBD with obvious symptoms endoscopic examinations are indicated.
A faecal calprotectin assay may be used as a screening test in cases where the symptoms are mild, but the levels may be low in CD of the proximal small bowel and in proctitis.
If diarrhoea is the principal symptom, a stool culture should be carried out in primary health care. A viral stool culture is indicated only rarely.
Most patients have a slightly elevated ESR level and the blood picture shows microcytic anaemia, but the values may also be totally normal.
Hypoalbuminaemia is often present in severe disease.
Endoscopic examinations in children and adolescents are done under general anaesthesia. In addition to ileocolonoscopy, an upper gastrointestinal endoscopy is also always indicated in order to make the differential diagnosis between CD and UC.
If growth retardation is evident, small bowel capsule endoscopy or magnetic resonance imaging is carried out after the endoscopic examinations.
Differential diagnosis
The most common cause of abdominal pain is constipation, and a small amount of blood on the surface of faeces usually originates from the distal rectum.
Haemorrhoids are rare in children and adolescents.
Occasional slight blood with stools may be the result of a juvenile polyp, which can be excised during endoscopic examination.
Treatment
Treatment guidelines are based on the management of IBD in adults (see articles Crohn's disease Crohn's Disease and Ulcerative colitis Ulcerative Colitis). The implementation of treatment calls for expertise in paediatric gastroenterology.
The management of iron deficiency anaemia may be initiated in primary health care (the maximum dose of iron is 100 mg/day since patients are rarely able to tolerate larger doses).
Childhood-onset IBD requires corticosteroids more frequently than the adult-onset disease - the disease is usually too extensive to respond to local therapies.
Surgery to relieve an isolated stricture in CD will effectively reverse growth failure.
Severe CD may be managed with exclusive enteral nutrition (EEN) in order to achieve remission.
Colectomy is indicated more frequently than in adult patients in the first years of disease due to an inadequate response to medication.
The management of severe disease as well as surgical intervention in young patients should be concentrated in university hospitals.