Post-Diarrheal Nutritional Trajectories Among Malnourished Children: A Clustering and Multinomial Modelling Approach

Although the co-occurrence of diarrhea and malnutrition is well documented, research has largely focused on the acute management of diarrheal illness. Despite its importance, longitudinal evidence characterizing post-diarrheal recovery trajectories is sparse. We sought to characterize post-diarrheal nutritional recovery trajectories among children aged 6-35 months who were malnourished at enrollment using data from the Enterics for Global Health (EFGH) Shigella Surveillance study (2022-2024). EFGH enrolled children aged 6-35 months presenting with medically-attended diarrhea and followed them at 4 weeks and 3 months post-enrollment. This analysis included children with baseline wasting, stunting, or underweight (z-score < -2) and complete anthropometric follow-up. Latent class mixed-effects models were used to identify distinct post-diarrheal growth trajectories based on changes in anthropometric z-scores over time. Multinomial modified Poisson regression models examined associations between baseline factors and trajectory membership. Among 9,480 enrolled children, 16.5% (n=1,561) were wasted, 22.7% (n=2,155) stunted, and 21.0% (n=1,994) underweight at baseline. Wasting showed greater recovery potential (80.8%) compared with stunting (38.5%) and underweight (40.3%). Recovery was shaped by factors across multiple levels. Clinical severity markers ( prolonged diarrhea, dehydration, and hypoxemia) increased the risk of nutritional failure. Age also influenced outcomes: infants were more likely to worsen, whereas older toddlers more often experienced stagnation. Interventions including exclusive breastfeeding, oral rehydration therapy, appropriate antibiotics, and zinc supplementation, improved outcomes, while unimproved sanitation undermined recovery. These findings highlight the need for integrated strategies combining infection control, nutritional rehabilitation, and water, sanitation, and hygiene interventions tailored to the childrens developmental stage. Key MessagesO_LIPost-diarrheal nutritional recovery is highly heterogeneous, with wasting showing the greatest potential for improvement, while stunting and underweight often result in persistent growth stagnation. C_LIO_LIBaseline anthropometric deficits alone are insufficient to predict recovery, highlighting the need for dynamic monitoring and individualized management. C_LIO_LIInfants are particularly vulnerable to acute nutritional deterioration, while older toddlers frequently experience growth stagnation. C_LIO_LIModifiable protective factors including exclusive breastfeeding, ORS, zinc, and appropriate antibiotics, improved outcomes, whereas poor sanitation undermined recovery. C_LIO_LIIntegrated strategies, tailored to a childs developmental stage, combining clinical care, nutrition, and environmental interventions are critical to support sustained child growth and development. C_LI