Intestinal biopsy (4 or more locations)

Intestinal biopsy (4 or more locations) — is an extended pathomorphological study of mucosal fragments taken from different anatomical parts of the colon and, if necessary, the terminal part of the small intestine. Such multifocal sampling of material (puncture biopsy) is the standard for a complete assessment of the condition of the entire intestinal tract, which allows to detect hidden pathologies and determine the exact spread of the disease.

Research objective: The main goal is to obtain a «panoramic» picture of the intestinal condition. This is necessary for patients with suspected inflammatory bowel disease (IBD), since the disease can have an «intermittent» nature (areas of damage alternate with healthy tissue). The study of four or more points minimizes the risk of diagnostic error and allows for a definitive diagnosis in complex clinical cases.

What does the pathologist evaluate:

• Histological mapping: comparative analysis of tissues from different sections (e.g., cecum, ascending, transverse, descending, sigmoid, and rectum).

• Inflammation activity: determination of the histological activity index for each localization separately.

• Crypt architecture: detection of deformation, atrophy, or branching of crypts, indicating a chronic course of the disease.

• Presence of granulomas: a key marker for differentiating Crohn's disease from ulcerative colitis.

• Epithelial dysplasia: searching for precancerous changes against the background of prolonged inflammation, which is important for patients with a long-term history of IBD.

Clinical significance: The results of such an extended biopsy allow the gastroenterologist to not only confirm the diagnosis, but also to classify the disease according to the Montreal Scale (determine the extent of colitis). This is critical for choosing the aggressiveness of therapy (biological therapy, immunosuppressants) and determining the prognosis. Evaluation of multiple sites is also the only way to diagnose pancolitis — inflammation of the entire colon.

When is it prescribed:

• primary diagnosis in case of suspected ulcerative colitis or Crohn's disease;

• long-term course of IBD (over 8–10 years) for oncoscreening and dysplasia detection;

• the need for differential diagnosis between nonspecific, infectious and ischemic colitis;

• chronic diarrhea of unknown etiology with a normal endoscopic picture (excluding microscopic colitis);

• assessment of achievement of complete histological remission against the background of treatment.