In ecological momentary assessment (EMA), respondents answer brief questionnaires about their current behaviors or experiences several times per day across multiple days. The frequent measurement enables a thorough grasp of the dynamics inherent in psychological traits, but it also increases respondent burden. To lower this burden, respondents may engage in careless and insufficient effort responding (C/IER) and leave data contaminated with responses that do not reflect what researchers want to measure. We introduce a novel approach to investigate C/IER in EMA data. Our approach combines a confirmatory mixture item response theory model separating C/IER from attentive behavior with latent Markov factor analysis. This allows for (1) gauging the occurrence of C/IER and (2) studying transitions among states of different response behaviors as well as their contextual correlates. The approach can be implemented using standard R packages. In an empirical application, we showcase the efficacy of this approach in both pinpointing C/IER instances in EMA and gaining insights into their underlying causes. In a simulation study investigating robustness against unaccounted changes in measurement models underlying attentive responses, the approach proved robust against heterogeneity in loading patterns but not against heterogeneity in the factor structure. Extensions to accommodate the latter are discussed.