Erythrocytes in Stool: Microscopic Morphology

Learn about the microscopic features of erythrocytes in stool. Understand why cells deform, leach, or retain shape in intestinal and gastric bleeding.

Anna Ivanova 1 min August 6, 2025

Stool sample with Lugol's solution, cluster of deformed erythrocytes

Stool microscopic preparation at high magnification, arrow indicates an intact erythrocyte

Erythrocytes in stool. Lugol’s solution preparation. 🙏 Images kindly provided by clinical laboratory diagnostics physician, Anna Ivanova, Moscow.

REFERENCE INFORMATION In stool, erythrocytes lose their smoothness due to:

Enzymes and acids - pepsin, hydrochloric acid (in gastric bleeding) - destroy the membrane.
Mechanical damage due to peristalsis.
Changes in pH and osmolarity in the intestine - cells shrink or swell.

Result: erythrocytes under the microscope appear deformed, fragmented, or colorless (leached). However, intact erythrocytes can also be found (one of them is indicated by an arrow in the second photo).