Fig. 8.1
Endoscopic images of pathological changes in the gastrointestinal tract in Crohn’s disease (a–c) and ulcerative colitis (d–f). Crohn’s disease: a Edematous mucous membrane with slight ulceration covered by fibrin in distal part of small intestine. b Pseudopolyps in sigmoid colon. c Stenosis of colon at a level of splenic flexure with extensive ulceration covered by fibrin. Ulcerative colitis: d Hemorrhagic stadium in sigmoid colon—edematous mucous membrane, redness and friability with flat erosions covered by fibrin. e Ulcerative stadium—flat ulceration covered by fibrin. f Polypoid stadium—several deep ulcerations covered by fibrin and pseudopolyps
Table 8.1
Endoscopic findings in patients with IBD
Crohn’s disease | Ulcerative colitis | |
|---|---|---|
Pattern of inflammation | Discontinous | Continous |
Involvement of rectum | − | + |
Involvement of ileum | + | − |
Perianal changes | + | − |
Fistulas | + | − |
Perforations | − | + |
Stenoses | + | − |
Mucosal pseudopolyps | + | − |
Additionally, the pathologist evaluates the samples acquired during the endoscopy. The histopathologic hallmark of CD are granulomas, which are not associated with the intestinal crypt injury and the transmural manner of inflammation (whole intestinal wall is affected). In specimens with UC, inflammation is usually limited to mucosa and appears as a widespread crypt distortion and crypt abscesses. Of note, none of these features has to be present in the early stage of the disease. The most prevalent microscoping abnormality seen within two weeks after the occurrence of the symptoms is basal plasmocytosis.
When CD is suspected, the upper GI endoscopy (also called “gastroscopy”) is recommended to confirm or exclude the involvement of the upper GI. Importantly, the procedure is of key significance in patients with symptoms suggesting any pathology in the upper GI tract and/or in unclassified colitis. The symptoms are as follows: heartburn, upper abdominal pain or discomfort, nausea, and belching. Biopsies should be taken from the duodenum and any suspicious lesions.
8.1.3 Visualization of the Small Bowel
In up to one-third of patients, the disease is strictly localized to the small bowel and in around 15 % of patients penetrating lesions develop. A detailed view of small bowel is far more challenging than the large bowel or stomach, even though the past decades brought a significant number or techniques with satisfying accuracy in recognizing lesions in the ileum and the jejunum. Currently, radiological and—to a lesser extent—endoscopic methods constitute a group of tests used in the imaging of small intestine. Following procedures are particularly useful in patients with a suspicion of CD or with unclear image during ileocolonoscopy.
Due to its complexity, visualization of the small bowel requires a specialist with good expertise, but there is still a place for a general practitioner, who can briefly explain the procedure to the patient and meet their any other demands. Nowadays, more and more patients demand from their practitioner a referral for particular procedures (such as magnetic resonance imaging (MRI) or capsule endoscopy). Overall it is a good sign, as these patients are often more engaged in the treatment process. However, the physician should clarify the needs of the patient and whether there is a need to perform particular procedures. Preferably, less invasive tests should be discussed in detail with the patient.
8.1.3.1 Ultrasonography
The most universal and cost-effective procedure is ultrasonography (US). At a first glance, US could be regarded as inefficient due to high interobserver variability and difficulties in viewing deeply situated loops. As a matter of fact, the utility of US in IBD has been proven in both, UC and CD. A recent meta-analysis which sought the diagnostic accuracy of US in detecting CD, showed that the sensitivity and specificity range from 75–94 % and 67–100 % in included studies, respectively (1). Such wide ranges resulted from a discrepancy in deciding on cut-off value of the bowel thickness by the authors of the studies. After statistical analysis of the data, sensitivity and specificity of 88 and 93 % were obtained, respectively, for a threshold of bowel thickness greater than 3 mm; when threshold greater than 4 mm was used, sensitivity and specificity of 75 and 97 %, respectively were achieved. What is more, US can detect colonic or small bowel inflammation with a sensitivity of 80–90 %. Despite the lack of ability to discriminate specific causes of inflammation, US could be regarded as an initial testing because of its noninvasiveness and low cost. Additionally, a recent prospective study reports about the usefulness of US in assessing the response of severe UC to therapy and tendency to accurately predict the course of the disease (2).
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