[Small intestinal biopsy--technique and diagnostic value (author's transl)].

The commonly used instruments for obtaining small bowel biopsies, their use and the examination of the biopsy particles by magnifying lens, light microscopy and histochemistry are presented. Based on biopsy findings, diseases of the small intestine are classified as follows: 1) diseases with diagnostic biopsy abnormalities which are excluded by a normal biopsy; 2) diseases which can be diagnosed by positive biopsy findings but cannot be excluded by a normal biopsy; 3) nonspecific mucosal abnormalities; and 4) diseases with normal architecture of the intestinal mucosa.