Lower left abdominal discomfort for a year, normal stool is less likely to be colon cancer, but can not completely exclude the possibility of colon cancer. Hidden pain and discomfort in the left lower abdomen can be seen not only in colon cancer, but also in colitis, colon polyps, irritable bowel syndrome and other diseases. 1. Colon cancer: colon cancer is a kind of malignant tumor of epithelial cells of colon mucosa, and patients may have the symptom of discomfort in the left lower abdomen. However, when colon cancer develops to a certain stage, it can be accompanied with changes of stool, including constipation, diarrhea, blood in stool, etc. Therefore, the possibility of suffering from colon cancer is small if the stool is normal, but colonoscopy and other examinations are still needed to determine it. 2. Colitis: patients with colitis may also have discomfort in the left lower abdomen for one year, but patients with colitis may have diarrhea, mushy stools, mucus, pus and blood stools, and other changes in stool habit and character. 3. Colon polyps: patients with colon polyps may also experience discomfort in the lower left abdomen for a year, with normal stool symptoms, but these patients may experience blood in the stool as the disease progresses. 4. Irritable bowel syndrome: Irritable bowel syndrome patients can also appear in the left lower abdomen uncomfortable symptoms for a year, but the patients of this disease can also be accompanied by constipation, diarrhea and other symptoms. If the symptoms of left lower abdominal discomfort for a year, normal stools, you should consult a doctor in time to find out the cause and ask the doctor to deal with it.