Magnetic resonance imaging is an exclusive imaging method which can distinguish injured tissues from the healthy tissues or organs without using ionizing radiation. Magnetic resonance imaging is able to provide quantitative data regarding the anatomical and physiological features of each specific organ. Magnetic resonance imaging is a non-invasive method, but contrast agents are necessary to enhance the visualization of inaccessible organs in some organs such as gastrointestinal (GI) imaging. Various types of contrast agents have been used in studies including intravascular administration and oral materials. Oral contrast agents can be the artificial materials or natural factors. Natural contrast agents consist of fruit juice or pulps. Some advantages have been reported regarding the natural types of contrast agents over the artificial agents including better taste and tolerability. We briefly reviewed the different types of contrast agents and focused on the studies in which natural oral contrast agents used to investigate their efficacy in increasing the gastrointestinal magnetic resonance imaging clarity.