Eating a cucumber in the morning and having pus and blood stool in the evening may be the cause of ulcerative colitis, bacillary dysentery, rectal cancer, etc., and should be treated according to the cause of the disease. Ulcerative colitis can be treated with mesalazine and prednisone; bacterial dysentery can be treated with levofloxacin; rectal cancer can be treated with surgery. 1. Ulcerative colitis: ulcerative colitis is a kind of autoimmune-related inflammatory bowel disease, diarrhea, pus and blood are its typical symptoms, mild to moderate can apply aminosalicylic acid preparation, such as salicylazosulfapyridine, mesalazine, medium and severe can be applied to glucocorticosteroids, such as prednisone, budesonide. 2. Bacterial dysentery: Bacterial dysentery is a kind of Shigella dysenteriae infection caused by the disease, the common symptom is diarrhea, abdominal pain, mucus, pus and blood stools, the treatment of the application of levofloxacin, ceftriaxone and other anti-infective treatment, combined with rehydration, to correct the electrolyte acid-base balance disorders. 3. Rectal cancer:Rectal cancer is a tumor of rectum, which can be manifested as pus and blood stool, and should be treated with surgery, chemotherapy or radiotherapy. Those who have pus and blood in stool should go to the hospital in time, improve the examination to find out the cause, and treat the cause under the guidance of doctor.