# Investigations Laboratory

Investigations Laboratory

A full blood count should be performed as anaemia is common, resulting from iron deficiency owing to blood loss, malabsorp tion or chronic disease. Vitamin B12 and folate deficiency may occur as a consequence of  terminal ileal disease or resection. - - Active inflammatory disease is usually associated with low ectal serum albumin, magnesium, zinc and selenium. Acute-phase protein measurements (C-reactive protein) and erythrocyte sedimentation rate may correlate with disease activity . An elevated faecal concentration of  calprotectin, a protein marker of  mucosal inflammation, may support a diagnosis of CD in patients with new onset of  persistent gastrointestinal symptoms. It can also be used to monitor disease activity in the long-term management of  established CD. - 

disease.
A: age at diagnosis
A1
≤
16 years old
A2
17–40 years old
A3
>40 years old
B (behaviour):
B1
In
/f_l
ammatory
progression
B2
Stenosing
B3
Penetrating
p
Perianal (can exist with any of
the above)
L: location
L1
Ileal
L2
Colonic
L3
Ileocolonic
L4
Upper digestive tract; can
be added to any of the three
above
After Silverberg MS, Daly MJ, Moskovitz DN
et al
. Diagnostic mis
-
classi
/f_i
cation reduces the ability to detect linkage in in
/f_l
ammatory
bowel disease genetic studies.
Gut
2001;
49
: 773–6.