(1) Figures of the incidence, case mortality, and duration in hospital of bacillary dysentery in previous campaigns are shown for comparison with those in the Middle Eastern theatre from 1939 to 1942. (2) The preventive measures are briefly outlined. (3) The question of bacteriophage in prophylaxis and treatment is discussed. (4) The early and later treatment of bacillary dysentery is described. (5) Evidence is given of the value of the sulphonamide group, especially sulphaguanadin, including tables of cases and results which show an improvement on previous campaigns.