There is a hard thing near the left lower abdomen near the hip bone, which can be seen in sigmoid colon tumor, leiomyosarcoma and other diseases. 1. Sigmoid colon tumor: it is one kind of colon tumor, and its main manifestations include change of defecation habit and fecal character, abdominal pain, abdominal mass, etc. The sigmoid colon is located in the left lower abdomen, so the abdominal mass occurs mostly in the left lower abdomen. The main treatment is surgical resection, which can be supplemented by chemotherapy (e.g. 5-FU, furazinouracil, etc.) and radiation therapy. 2. Rhabdomyosarcoma: also known as myofibroma, is a kind of fibrous tissue sarcoma from muscle tissue. It can occur in any part of the body, the most common one is leiomyosarcoma near rectus abdominis muscle on the abdominal wall, and it can also be seen in the left lower abdomen. Early growth is slow, smooth and easy to push, hard texture, if mixed with other components, it is called fibromyosarcoma, fibroadenoma, fibrolipoma and so on. The common treatment is surgical excision. There is a hard thing in the left lower abdomen near the hip bone, we should consult a doctor in time, improve the examination, make a clear diagnosis and then carry out professional diagnosis and treatment in time.