The manifestation of rectal cancer metastasis to bone is mainly back pain or bone pain, which depends on the site of bone metastasis, such as metastasis to limb bones, which is mainly pain in limb bones, or pain aggravated after activities. If the metastasis is in the spine, it mainly manifests as back pain, and in severe cases, it can appear numbness of both lower limbs, incontinence, or even paraplegia. If it is metastasis to skull, it is mainly headache. Therefore, bone metastasis of rectal cancer mainly manifests as pain, at this time, bone scan or magnetic resonance examination can find filling defects or multiple low density foci, so as to make clear diagnosis. In conclusion, rectal cancer is prone to bone metastasis and the symptoms of bone metastasis are mainly pain.