Simulated tissue structures for practicing surgical techniques and methods of manufacturing those structures are provided. In particular, a realistic organ model or simulated tissue portion for practicing the removal of a tumor or other undesired tissue followed by suturing a remnant defect as part of the same surgical procedure is provided. The simulated tissue structures include a polyp simulation having a suturable mesh layer that is separable from a defect layer. A simulated colon model with interchangeable and suturable tissue pods is also provided as is a fully suturable rectum model and a rectum model with integrative suturable and removable polyp zones.