I. Differential diagnosis of abdominal pain
Abdominal pain refers to a series of warning signals of protective defensive reactions caused by functional malfunction or organic lesions of the internal and external organs of the abdominal cavity caused by various reasons, which stimulate the abdominal nerves. Abdominal pain can be divided into acute abdominal pain and chronic abdominal pain according to the degree and urgency of its occurrence. Generally speaking, most of the abdominal pain caused by internal diseases is chronic abdominal pain, while acute abdominal disease is a group of diseases characterized by acute abdominal pain caused by intra-abdominal organ lesions, characterized by many diseases, rapid onset, rapid development, many changes, heavy conditions and complex etiology. Because of the wide variety of diseases causing acute abdominal pain, the close proximity of various organs in the abdominal cavity, the complex and variable clinical manifestations, and the inconsistent response and tolerance of different patients to abdominal pain, it is easy to cause missed diagnosis, misdiagnosis, and even misdiagnosis. Therefore, in the diagnosis of abdominal pain, it is necessary to grasp the main points, comprehensive analysis and careful identification to prevent misdiagnosis and mistreatment.
Second, the causes and manifestations of abdominal pain
Abdominal pain can have different manifestation characteristics depending on the organ and nature of the lesion: generally, there can be visceral pain, somatic pain and involvement pain; persistent pain, paroxysmal pain, paroxysmal intensification of persistent pain; and different descriptions and feelings of acute abdominal pain and chronic abdominal pain. Numerous diseases cause abdominal pain, mostly in the abdomen, but a few are also caused by non-abdominal diseases.
Abdominal lesions.
1, inflammatory diseases: such as peritonitis, appendicitis, cholecystitis, liver abscess, pancreatitis, acute gastroenteritis, inflammatory bowel disease, urinary tract infection, etc.
2.Organ obstruction or torsion: caused by obstruction of cavity organs or ducts. Such as intestinal obstruction, intussusception, cholelithiasis, ureteral stones, pancreatic duct stones, biliary ascariasis, acute gastric torsion, large omental torsion or ovarian cyst torsion, etc.
3, abdominal organ perforation or rupture: such as gastroduodenal ulcer perforation, intestinal perforation, gallbladder or bile duct perforation, liver and spleen rupture, liver cancer rupture, pancreatic injury, ectopic pregnancy rupture, ovarian cyst rupture, etc.
4, vascular lesions: such as mesenteric vascular thrombosis or embolism, portal vein thrombosis, intercalated aneurysm, splenic infarction, renal infarction, etc.
5, abdominal wall diseases: such as abdominal wall trauma, abdominal wall herpes zoster, abdominal wall neuralgia, etc.
6, intra-abdominal organ peritoneal overstretching: such as liver stasis and enlargement, intestinal mesentery being overstretched, etc.
7, lesion invasion of intra-abdominal nerve: such as pancreatic tumor invasion of the abdominal plexus, etc.
8, other: such as intestinal spasm, acute gastric dilatation, dysmenorrhea, etc.
Extra-abdominal lesions.
1, chest diseases: some chest diseases such as acute pneumonia, pleurisy, pulmonary infarction, pneumothorax, and even bronchial asthma can also cause abdominal pain. Acute abdominal pain caused by pneumonia is mostly related to the more severe disease, inflammation involving the diaphragm pleura. Cardiovascular diseases such as angina pectoris, acute myocardial infarction, pericarditis, and ruptured aortic coarctation aneurysm also often have abdominal pain. The mechanism of abdominal pain caused by acute myocardial infarction is mainly due to the stimulation of the vagus nerve during myocardial ischemia and hypoxia, which has a reflex effect on the stomach and intestines. In addition, diseases such as mediastinal inflammation or tumor can sometimes cause abdominal pain.
2, central nervous system diseases: such as cerebrovascular accident, encephalitis, etc. sometimes accompanied by abdominal pain. Occasionally, brain tumors have also been reported to cause abdominal pain. In abdominal epilepsy, abdominal pain mostly occurs during severe headache or migraine. The mechanism of abdominal pain is caused by abnormal discharges in the vegetative nerve center and nearby parts of the intestinal tract causing the release of large amounts of acetylcholine from the vegetative nerve endings, resulting in severe abdominal pain due to spasm of the smooth muscle of the intestinal tract. In addition, spinal cord tumor, spinal cord tuberculosis, arachnoiditis, etc. can also cause abdominal pain.
3, spinal diseases: such as scoliosis, spondylitis, spinal arthritis, thoracic spine tuberculosis, spinal metastases, intervertebral disc herniation, etc. can compress the nerve roots and abdominal pain, and the pain is more aggravated when twisting, flexing, coughing and defecating. In addition, osteoporosis and other diseases can also cause abdominal pain.
4, blood and hematopoietic system diseases: such as hereditary spherocytosis, acute hemoglobin anemia can cause severe abdominal pain when hemolysis occurs. Paroxysmal sleep hemoglobinuria and paroxysmal cold hemoglobinuria can induce abdominal pain due to sleep or cold. Abdominal pain can also occur in hemoglobinopathies such as sickle cell disease and thalassemia. Abdominal allergic purpura is a common vascular allergic disease, due to the body’s allergic reaction to certain allergenic substances, resulting in increased capillary fragility and permeability, extravasation of blood, producing skin purpura, mucosal and certain organ bleeding. When the mucosa of the gastrointestinal tract and the capillaries of the dirty peritoneum are involved, it manifests as abdominal pain, often paroxysmal colic, mostly located around the umbilicus, lower abdomen or the whole abdomen, which can be misdiagnosed as surgical emergency abdomen during the attack due to abdominal muscle tension, obvious pressure pain and hyperactive bowel sounds. Acute leukemia and malignant lymphoma may also have episodes of severe abdominal pain. In addition, splenic infarction caused by hemolytic anemia, leukemia and myelofibrosis may present with pain in the left quadrant of the rib cage.
5, endocrine and metabolic diseases: such as diabetic ketoacidosis causes abdominal pain mainly due to severe dehydration, electrolyte disorders and acidosis stimulating gastrointestinal nerves, causing spasm of gastrointestinal smooth muscle. In addition, the oxygen dissociation curve shifts to the left in acidosis, and blood oxygen dissociation is difficult, resulting in severe hypoxia in gastrointestinal tissues, producing large amounts of acetoacetic acid, β-hydroxybutyric acid and pyruvic acid, plus a large amount of acidic metabolites produced after protein decomposition, all of which stimulate nerves and cause gastrointestinal dysfunction, leading to abdominal pain. Abdominal pain also occurs in primary hyperthyroidism and other conditions. Hyperlipidemia can also cause abdominal pain. Porphyrias, especially acute intermittent porphyrias, can also cause abdominal pain. Amyloidosis, especially primary systemic amyloidosis, can also lead to abdominal pain.
6, infectious diseases: such as epidemic hemorrhagic fever can lead to systemic capillary and small vessel damage, abdominal organ congestion, exudation, edema can cause severe abdominal pain, pressure pain, rebound pain, and even ascites. Abdominal pain caused by tetanus is mainly due to exotoxin, especially spasmotoxin, which has a special affinity for nerves and causes paroxysmal spasms of the abdominal muscles, resulting in abdominal pain. Scarlet fever caused by bacterial infections can be accompanied by right lower abdominal pain, which can be easily misdiagnosed as acute appendicitis. Abdominal pain caused by rickettsial and certain viral infections is also common. Acute abdominal pain in AIDS patients may be secondary to cytomegalovirus enteritis, opportunistic infections, lymphoma or Kaposi’s sarcoma of the gastrointestinal tract.
7. Parasitic diseases: The migration of adult parasites or larvae in the host’s body and penetration of tissues can often cause more severe abdominal pain. In addition, gastrointestinal malaria such as Plasmodium falciparum or Plasmodium inter vivax can also cause abdominal pain.
8, poisoning and electrolyte disorders: for example, acute lead poisoning often has severe abdominal pain episodes, others such as poisonous spider poisoning can have abdominal cramps. Uremia can also have abdominal pain. Electrolyte disorders and acid-base balance disorders can often cause abdominal pain, such as hyponatremia, hypokalemia and hypercalcemia, etc.
9, connective tissue diseases: most of the abdominal pain caused by connective tissue diseases is due to pancreatitis, abdominal organ infarction or thrombotic vasculitis, etc. The mechanism of abdominal pain in SLE is mainly due to the extensive deposition of immune complexes in the gastrointestinal vessels and the occurrence of vasculitis, which causes increased permeability of capillary walls, resulting in abdominal pain, ascites and other symptoms. Periarteritis nodosa can cause mesenteric vascular thrombosis and abdominal organ infarction leading to episodes of abdominal pain. In addition, dermatomyositis, systemic scleroderma, and rheumatic fever also often cause abdominal pain. Abdominal urticaria can often appear all over the skin, itching, paroxysmal abdominal pain, pressure pain is obvious but no muscle tension and rebound pain, a few patients abdominal pain can precede the emergence of wind mass, very few have abdominal pain without wind mass, more easily misdiagnosed.
10, physical and mental diseases: abdominal pain can also appear due to uneasiness, tension, anger, depression or hysteria caused by medical origin, stress or other special stimuli.
Third, postoperative abdominal pain
Patients have different degrees of pain in the early postoperative period due to surgical trauma or the release of inflammatory mediators and cytokines, or incomplete cleaning of chemical irritants in the abdominal cavity, organ or tissue congestion, edema or ischemia in the early postoperative period, etc. However, incisional pain is the most common cause of abdominal pain after abdominal surgery, which usually lasts for 24 hours and gradually decreases after the next day, and can last for 72 hours or longer in a few patients. With the recovery of gastrointestinal function after surgery, some patients may have spasmodic abdominal pain due to the increase of intestinal peristalsis, which can be relieved once the anus is exhausted. If the patient reappears with abdominal pain after anal venting, or reappears without anal venting, the possibility of surgical complications should be considered. In case of abdominal pain after gastroduodenal, small intestine or colorectal surgery, complications such as anastomotic leak, obstruction or rupture of duodenal stump should be excluded first, and early postoperative intestinal adhesions, intestinal torsion, mesenteric vascular embolism or intra-abdominal hernia should be considered. In case of abdominal pain after hepatobiliary surgery, bile leak, intrahepatic hematoma, subdiaphragmatic infection or abscess, hemocholestasis, residual bile duct stones or bile duct stones left after cholecystectomy should be excluded. In case of abdominal pain after pancreatic or spleen surgery, pancreatic leak, pancreatitis, left subdiaphragmatic infection or abscess should be ruled out first. In the case of abdominal pain appearing early after abdominal trauma patients, one should think of any omission of comprehensive management of multiple injuries, etc. In the case of abdominal pain after surgery for an incarcerated hernia, consideration should be given to whether there is any omission of the blood flow of the intestinal canal in retrograde incarcerated hernia and whether there is necrosis of the intestinal canal after retraction of the whole incarcerated hernia. If postoperative abdominal pain is accompanied by abdominal muscle tension or rebound pain, the possibility of postoperative complications of peritonitis should be considered. For patients with abdominal pain after surgery such as malignant tumor or portal hypertension, it is especially important to be alert to the presence of complications such as thrombosis of the portal venous system.
IV. Accompanying symptoms of abdominal pain
Most abdominal pain is often accompanied by other symptoms, which are often related to the cause of abdominal pain: 1.
1, abdominal pain accompanied by fever: often suggests infection or inflammatory lesions in the abdominal organs. Those with sudden onset of hyperthermia often suggest more serious infection poisoning, such as acute diffuse peritonitis, sepsis, severe acute cholangitis, acute gangrenous appendicitis, liver abscess or abdominal abscess, etc. Irregular fever with slow onset is more often seen in malignant tumors, connective tissue diseases, etc. If the fever is low in the afternoon, it may be abdominal organ tuberculosis.
2, abdominal pain with vomiting: mainly seen in inflammation of abdominal organs, such as acute gastroenteritis, acute cholecystitis, etc., also seen in gastrointestinal obstruction, such as pyloric obstruction, intestinal obstruction, etc., or seen in biliary or urinary stone obstruction and other diseases.
3.Abdominal pain with diarrhea: It can be seen in acute gastroenteritis, allergic purpura, intestinal tuberculosis, intestinal tumor, etc., and also in pelvic abscess or effusion, etc.
4, abdominal pain with bloody stools: sudden onset can be seen in acute bacterial dysentery, intestinal entrapment, acute hemorrhagic necrotizing enterocolitis, allergic purpura, etc. Chronic cases can be seen in chronic dysentery, chronic colitis, intestinal tumors, etc.
5, abdominal pain with hematuria or painful urination: common in urinary stones or infection.
6, abdominal pain with chest pain or arrhythmia: common in myocardial infarction or angina pectoris, etc.
7, abdominal pain with cough or shortness of breath: may be pneumonia or pleurisy, etc.
8, abdominal pain with menstrual disorder or vaginal bleeding: gynecological diseases such as ectopic pregnancy rupture should be considered.
9, abdominal pain with radiating pain: with pain in the left lower back should be considered acute pancreatitis or pancreatic cancer, etc.; while with pain in the right shoulder may be acute cholecystitis.
10, abdominal pain with abdominal mass: abdominal pain patients with abdominal masses and fever and obvious pressure pain can be seen in appendiceal abscess, abdominal cavity