Is diarrhea and constipation alternating cancer?

Constipation and diarrhea may be caused by cancer such as colon cancer, rectal cancer, etc., but may also be caused by peptic ulcer, colitis, Crohn's disease, etc. You need to go to the hospital for colonoscopy for identification. If there is a malignant tumor disease, you need to go to the hospital for surgery as soon as possible.