The objective of this paper is to understand how policy discourse transformations generate ambiguity in the way health service innovation unfolds. Past research does not produce a systematic understanding of the discourse mechanisms through which policy discourse produces ambiguity and contradictions in health service innovation. Our study fills this gap by focusing on how new and emerging policy discourses can be more ore less effective in
challenging the hegemony of a dominant policy discourse. We define these emerging policy discourses as “thorns”, since they produce alternative models of reforming the health sector challenging the establishment and its interests. Drawing on the concept of “muscularity of discourse”, we explore the value of frame theory and narrative analysis in the case of health sector reforms in Kenya, with a specific focus on the deployment of health information systems. The case study takes an historical perspective to illustrate how the dialectic between competing narratives informing international health policies influenced efforts to modernize the health sector in Kenya. Our study makes the following contribution. First, it demonstrates how the good intentions of those challenging the establishment, can lead to controversial effects such as contradictions and inefficiencies in the way the health sector is managed. Second, it highlights the danger of assimilating local stakeholders into an overarching narrative of change constraining the emergence of alternative models that are more responsive to the need of local populations.