Left abdominal flexion is one of the clinical manifestations of splenic trauma. The typical symptom of simple splenic rupture is that after a direct blow to the left upper abdomen or a severe fall and impact, the child cannot stand upright immediately, especially with left abdominal flexion. The child cannot even stand up, and the lying position likes the left side downward and waist forward bending, not daring to move. The spleen is located deep in the left lower thoracic region, weighing about 75-150 grams, and is one of the most vulnerable organs in the abdominal cavity, with the incidence of spleen injury being as high as 40-50% in various abdominal traumas. Splenic rupture caused by traffic accidents is the most common (about 50%-60%), followed by injuries from falls, blows, bruises and stab wounds. Differential diagnosis of left abdominal flexure: palpable painful mass in the left lower abdomen: can be seen in ulcerative colitis, rectal and sigmoid colon cancer. Schistosomal granuloma of the rectum and sigmoid colon, left ovarian cystitis, etc. Tonicity of abdominal muscles: it is one of the clinical manifestations of acute appendicitis. Acute appendicitis often starts as epigastric pain or full abdominal pain, gradually confined to the point of marsupial, with more prominent nausea and vomiting, pressure pain, rebound pain and abdominal muscle tonicity are more obvious. Acute appendicitis is a common surgical condition that ranks first among all kinds of acute abdominal diseases. 1886 Fitz first named it, and in 1889 McBurney proposed the idea of surgical treatment of this disease. However, the condition of acute appendicitis varies a lot, so each specific case should be treated seriously, with thorough history taking and careful examination so that accurate diagnosis can be made, early surgery can be performed and complications can be prevented to improve the cure rate. Lower left abdominal pain: lower left abdominal pain with abdominal pain and diarrhea may be colitis. Colitis abdominal pain is usually vague or colic, often located in the lower left abdomen or small abdomen. Other manifestations include loss of appetite, abdominal distension, nausea, vomiting, and hepatomegaly; there may be pressure pain in the left lower abdomen, and sometimes a spastic colon can be palpated. Left lower abdominal pain is usually a problem of the sigmoid colon, left ovary and fallopian tube, and left ureter.