Oral rehydration salts and zinc for childhood diarrhoea in Bangladesh, 2019 and 2025: coverage, wealth inequality and reported source of care

Background: Diarrhoea remains a major cause of morbidity and mortality among children under five. WHO and UNICEF recommend oral rehydration salts (ORS) alongside 10 to 14 days of zinc supplementation. However, national progress in combined treatment coverage and its socioeconomic and care-related inequalities remains insufficiently understood in Bangladesh. We assessed combined coverage, wealth inequality and differences by reported source of care. Methods: We analysed children under five with caregiver-reported diarrhoea in the 2019 (n=1,589) and 2025 (n=1,634) Multiple Indicator Cluster Surveys (MICS). We estimated combined coverage using design-based methods, wealth inequality using slope indices, and associations with source of care using pooled adjusted prevalence ratios (aPR). Demographic and Health Survey (DHS) estimates provided an external comparison. Results: Combined ORS and zinc coverage increased from 35.0% (95% CI 32.3 to 37.7) in 2019 to 42.9% (40.1 to 45.8) in 2025. In 2025, ORS and zinc coverage were 75.8% and 51.9%, respectively. The 2025 estimate agreed with DHS 2022, whereas MICS 2019 was below DHS 2017-18. Wealth inequality persisted in 2025 (slope index 13.0 percentage points, 3.4 to 22.6). Adjustment attenuated the pooled slope index from 11.8 to 6.5 points (-1.7 to 14.6). Coverage was lower with pharmacy-only than public care (aPR 0.59, 0.53 to 0.66) and with no care reported (0.14, 0.11 to 0.18). Children with no care reported accounted for 43.7% of children without combined treatment in 2025. Conclusions: Combined coverage increased, although the apparent progress may be overstated by the lower MICS 2019 estimate relative to DHS. Zinc remained the larger treatment gap, while one in four children received no ORS. Reported sources of care require cautious interpretation.