The effect of orally administered immunoglobulin (IgAbulin) on chronic non-specific diarrhoea of infancy was studied in seven children, median age 26 (21-36) months and duration of diarrhoea 32 (18-84) weeks. Routine laboratory tests for malabsorption and small bowel biopsies were taken in all children before and after 3 weeks of IgAbulin treatment. The biopsy specimens were analysed with regard to histopathology, electronmicroscopy, immunohistochemistry and microbiology. The number of stools decreased from a median of 4.0 (3.0-5.0) to 1.5 (1.0 3.5) (p < 0.05) stools per day over the study period.