Chronic colitis lower left abdominal pain may be caused by dietary disorders, intestinal mucosal bleeding, intestinal muscle spasm and other reasons. 1. Dietary disorders: after overeating or eating irritating food, chronic colitis patients may lead to an acute attack of chronic colitis, resulting in lower left abdominal pain, which may be accompanied by nausea, vomiting, diarrhea and other symptoms. 2. Bleeding of intestinal mucosa: If chronic colitis is more serious, it affects the surrounding blood vessels, resulting in localized bleeding of the intestinal mucosa, causing pain in the lower left abdomen. 3. Intestinal muscle spasm: left lower abdominal pain is usually a clinical manifestation of chronic colitis, prolonged chronic colitis may lead to abdominal muscle spasm or vasospasm, the symptoms of left lower abdominal pain. Patients with chronic colitis pain in the lower left abdomen should go to the hospital in a timely manner, under the guidance of a professional physician to clarify the specific causes, and follow the doctor’s instructions for treatment. Usually should pay attention to dietary moderation, avoid eating cold and unclean, stimulating food.