Pink stool may be caused by physiological reasons, or it may be caused by gastrointestinal bleeding due to pathological reasons such as ulcerative colitis or rectal cancer. 1. Physiological reasons: eating a lot of fruits and vegetables rich in red pigment, such as dragon fruit, watermelon, etc., these pigments are not absorbed by the intestinal tract, and when they are discharged along with the feces, it can lead to pink stool. 2. Ulcerative colitis: the intestinal mucosa of patients with ulcerative colitis has diffuse inflammation, and the inflammation stimulation leads to congestion, swelling and focal bleeding of the intestinal mucosa, and when the bleeding position is low, the blood can be mixed with the feces to form pink feces. 3. Rectal cancer: when rectal cancer patient’s rectal wall is invaded by tumor tissues, bleeding and necrosis of tumor tissues or invasion of intestinal mucous membrane blood vessels can cause intestinal bleeding, and the mixture of blood and feces can form pink stool. Therefore, patients with pink stool should go to the hospital in time, complete the examination, and follow the doctor’s instruction to carry out targeted treatment to clarify the cause of the disease.