Considerable success in the management of chronic diarrhoea has been reported using a modular diet (MD), with gradual increments in every nutrient toward a full-strength formula. As the commercially prepared constituents are unavailable in Croatia, we have developed a home-made MD based on boiled minced chicken meat, sunflower oil emulsion, sucrose and cornflour. A full range of vitamins and minerals are added. The value of this MD was compared to a semi-elemental formula (SF) Pregomin. Eighteen infants with severe chronic diarrhoea were randomly assigned to receive either MD of SF. Both groups were comparable with respect to sex, age, and degree of malnutrition. Duration of diarrhoea, fed tolerance, anthropometry, and biochemistry were compared after 4 weeks of treatment. Results: (1) diarrhoea was significantly shorter (3 vs 7 days;P<0.01) and nutritional recovery started earlier (5 vs 9 days;P<0.01) in MD group; (2) median weight gain in the SF group was 100 g/week, compared to 171 g/week in MD group (P<0.05); (3) in two patients from the SF group, diarrhoea persisted, but they achieved complete recovery when changed to MD. A MD made in the hospital kitchen was superior to a SE formula in the treatment of chronic diarrhoea of infancy.