Liver cancer patients’ left lower abdominal pain and diarrhea are usually related to intestinal infection, decreased function of gastrointestinal tract and metastasis of cancer cells. 1. Intestinal infection: patients with liver cancer have poor immunity and are easily infected with bacteria, viruses and other microorganisms, and the repeated stimulation of intestinal mucous membrane by disease-causing bacteria will accelerate intestinal peristalsis, which will cause pain in lower left abdomen and diarrhea and other symptoms. 2. Decrease in gastrointestinal function: when some liver cancer patients develop into middle or advanced stage, their gastrointestinal function will be obviously weakened, and they are prone to suffer from indigestion and gastrointestinal flatulence after eating, which will lead to symptoms such as pain in the left lower abdomen and diarrhea. 3. Cancer metastasis: When liver cancer develops into advanced stage and the cancer cells have metastasized to the gastrointestinal tissues, symptoms such as lower abdominal pain and diarrhea will appear, which will lead to emaciation, body weakness and fatigue. When liver cancer patients have left lower abdominal pain and diarrhea, they should consult a doctor in time and treat the disease according to the guidance of a professional doctor, so as to avoid delaying the condition and causing the cancer cells to spread to other parts of the body.