We characterize effective descent morphisms of what we call filtered preorders, and apply these results to slightly improve a known result, due to the first author and F. Lucatelli Nunes, on the effective descent morphisms in lax comma categories of preorders. A filtered preorder, over a fixed preorder \( X \), is defined as a preorder \( A \) equipped with a profunctor \( X\to A \) and, equivalently, as a set \( A \) equipped with a family \( (A_x)_{x\in X} \) of upclosed subsets of \( A \) with \( x'\leqslant x\Rightarrow A_x\subseteq A_{x'} \).