The sigmoid colon is located in the left lower abdomen and the small pelvis, and is curved in the shape of “B”. The sigmoid colon is a part of the colon with a length of about 40cm, located in the left lower abdomen and small pelvis, which originates from the descending colon, turns into the pelvis at the left iliac fossa, and connects to the rectum underneath, and is curved in the shape of a “B” in its entire length. The sigmoid colon is a peritoneal endoprosthesis, which is connected to the left posterior wall of the pelvis by the sigmoid colon mesentery. Because of the greater activity amplitude of the middle part of the sigmoid colon, the sigmoid colon is prone to torsion. In addition, the sigmoid colon is also a good site for diseases such as diverticula and tumors. If you have abdominal pain, abdominal distension or abnormal bowel movement and other symptoms, you should consult a doctor in time to find out the cause of the disease and follow the doctor’s instructions for further treatment or therapy.