The specific mechanisms of faecal bacterial removal by constructed wetland (CW) mechanisms are inadequately understood. In several circumstances, CWs have been compared to "black box" systems involving poorly understood waste removal mechanisms despite being an emerging environmentally friendly waste management approach. This has therefore attracted numerous scientific studies to further unlock CWs' functional mechanisms and to increase its efficiencies. This review paper covers detailed information on the status of detection techniques and removal efficiencies of faecal coliforms, with an emphasis on Escherichia coli. A comprehensive literature search was undertaken that involved a comparative review of various study results and critical analysis of previous scientific and review papers. The ultimate objective is to shed further light on the role of wetlands on wastewater purification for improved aquatic ecosystem health and clean water for humans and other organisms.