Wireless capsule endoscopy (WCE) has emerged as a promising alternative to traditional endoscopic procedures. However, these systems cannot be accurately assessed due to the lack of affordable and readily available gastrointestinal tissue phantoms. With the aim of overcoming this limitation, the current work presents tissue phantom recipes for oesophagus, stomach, small intestine and colon which cover some narrow (400-450 MHz, 900-950 MHz, 2.4-2.5 GHz and 5.7-5.9 GHz) and broad (0.4-3 GHz, 0.4-6 GHz and 3.1-10.75 GHz) frequency bands. The proposed recipes avoid the use of sugar, and are thus very stable over time.