Rectal ca generally refers to rectal cancer. The colonoscopy results show that rectal cancer is not considered to be diagnosed, and pathological examination is usually needed. Patients are advised to actively cooperate with doctors for treatment and improve relevant examinations. Colonoscopy result showing rectal cancer refers to the discovery of lesions suspected to be malignant tumors of the rectum during colonoscopy. Generally the doctor will take out a small part of the lesion tissue and conduct pathological examination to clarify the nature of the lesion. If the pathological examination result is rectal malignant tumor, only then the diagnosis of rectal cancer can be confirmed. Doctors will also combine the patient’s clinical manifestations and the results of fecal occult blood test, tumor marker examination, ultrasonography, CT examination and MRI examination to make a comprehensive diagnosis. Identifying the stage of rectal cancer and checking whether the tumor shows peripheral or distant metastasis in order to make corresponding treatment plan.