Although World Health Organization (WHO) rehydration management guidelines (Plan C) for severe dehydration are widely practiced in resource-poor settings, they have never formally been tested in a clinical trial, despite outcomes (mortality) in this group of children being poor. As the Fluid Expansion as a Supportive Therapy trial raised concerns regarding the safety of fluid bolus therapy for septic shock, we evaluated current recommendations (aggressive rehydration therapy) versus a slower more conservative rehydration regime in Ugandan/Kenyan with severe dehydration secondary to gastroenteritis. We found the slower regime giving rehydration therapy over 8 hours to be safe and for clinicians it was easier to implement than the aggressive two-stage Plan C regime recommended by WHO. Time correct signs of dehydration and hospital stay was similar in the two groups. Future large trials with mortality as the primary endpoint are warranted.