The proposed functions of the intestinal cells of Cajal (ICC) are to, 1) pace the slow waves and regulate their propagation, 2) mediate enteric neuronal signals to smooth muscle cells, and 3) act as mechanosensors. In addition, impairments of ICC have been implicated in diverse motility disorders. This review critically examines the available evidence for each of these roles and offers alternate explanations. This review suggests that: 1) The ICC may not pace slow waves or help in their propagation. Instead, they may help in maintaining the gradient of resting membrane potential in the circular muscle layer, which stabilizes the slow waves and enhances their propagation. The impairment of ICC destabilizes the slow waves, resulting in attenuation of their amplitude and impaired propagation. 2) The one-way communication between the enteric neuronal varicosities and the smooth muscle cells occurs largely by volume transmission, rather than by wired transmission via the ICC. 4) There are fundamental limitations for the ICC to act as mechanosensors. 4) The ICC are impaired in almost every clinical motility disorder. However, a cause-and-effect relationship between the ICC impairment and motility dysfunction is not established. The ICC impair readily, and transform to other cell types in response to alterations in their microenvironment, which have limited effects on motility function. Concurrent investigations of the alterations in slow waves, excitation-contraction and excitation-inhibition couplings in smooth muscle cells, neurotransmitter synthesis and release in enteric neurons and the impairment of the ICC are required to understand the etiologies of clinical motility disorders.