The causes of left lower abdominal distension are very many: first, it may be intestinal problems, which is one of the most common causes. Many intestinal diseases can cause left lower abdominal distension, such as ulcerative colitis, intestinal flatulence, indigestion, acute and chronic inflammation of the intestinal tract, and other diseases. Second, it may be substantial organ diseases, such as pelvic and abdominal cavity diseases, which can also produce symptoms of left lower abdominal distension and pain, such as acute pelvic inflammatory disease, pyelonephritis, cystitis, kidney stones, ureteral stones and other diseases. Third, consider ectopic pregnancy in women and pregnancy rupture, which can lead to a feeling of distension and pain in the abdomen of women. In addition to the above-mentioned reasons, it may be caused by tumors. If the patient’s abdominal distention pain does not heal after a long period of time, it is recommended to go to a regular hospital for a detailed examination to determine the specific cause for treatment.