Ileocecal syndrome

　　1. Etiology

　　The exact etiology of this syndrome has not been clarified, and it is generally believed to be related to factors such as granulocytopenia, intestinal infiltration of leukemia cells, the application of strong chemotherapy drugs (especially cytarabine), and secondary infection.

　　2. Pathogenesis

　　Leukemia can cause widespread involvement of the gastrointestinal tract, with possible colonic mucosal hemorrhage, necrosis, small intestinal mucosal ulcers, ileal perforation, appendicitis. This syndrome often involves the ileocecal region and the right half of the colon, and the possible reason is that this area has abundant lymphoid tissue, a wider lumen, and thicker intestinal wall, making it easy to secondary mucosal ischemia and bacterial infection. Leukemia infiltration is the pathogenesis of this syndrome, and the application of strong chemotherapy drugs and secondary infection during granulocytopenia are the direct causes of the disease.

　　1. Toxic megacolon

　　It occurs during the acute active phase with an incidence of about 2%. It is caused by inflammation affecting the colon muscular layer and the interspersed nerve plexus, leading to reduced intestinal wall tension, segmental paralysis, and a large accumulation of intestinal contents and gas, causing acute colonic dilation. The intestinal wall is thin, and the lesions are often seen in the sigmoid colon or transverse colon. Triggers include hypokalemia, barium enema, and the use of anticholinergic drugs or opiate drugs, etc. Clinical manifestations include rapid deterioration of the condition, obvious toxic symptoms, accompanied by distension, tenderness, rebound pain, decreased or absent bowel sounds, increased white blood cells, and X-ray abdominal films showing widened intestinal lumen and disappearance of colonic haustra. It is prone to complications such as intestinal perforation, with a mortality rate of 11% to 50%.

　　2. Ulcer perforation

　　It is prone to cause ulcer perforation and acute diffuse peritonitis on the basis of colon dilation.

　　3. Ulcer bleeding

　　In addition to bleeding due to ulceration involving blood vessels, hypoprothrombinemia is also an important cause. It often requires treatment due to the large amount of bleeding.

　　4. Canceration

　　The occurrence of cancer is related to the duration of the disease and the extent of the lesion. The longer the course, the wider the range, the more cancerous changes. The incidence is about 5%, ten times higher than that of those without colitis, and is more common in those with colitis involving the entire colon, onset in childhood, and a history of more than 10 years.

　　5. Colon stenosis and intestinal obstruction

　　During the healing process, a large amount of fibrous tissue can form scars that cause colon stenosis and intestinal obstruction, which is more common in the distal colon.

　　The clinical manifestations of this syndrome are mainly fever, abdominal pain, distension, diarrhea, bloody stools, nausea, and vomiting during the period of granulocytopenia. The granulocyte count may be significantly reduced, below 0.5×109/L, with a body temperature of 38～39℃. Abdominal pain is usually persistent right lower quadrant pain, similar to appendicitis; it can also be diffuse pain, similar to peritonitis. Severe diarrhea can cause distension, dehydration, and electrolyte disturbance, with stool nature varying from watery to jam-like bloody stools. In severe diarrhea complicated with sepsis, circulatory failure may occur, with a mortality rate of up to 80%.

　　In the treatment of various blood system diseases, it is necessary to strengthen supportive therapy and strictly prevent and treat various secondary infectious diseases. For very small or premature infants with illness, feeding can be delayed for several days or weeks by using total parenteral nutrition, and then slowly increased over several weeks, which can reduce the occurrence of necrotizing enterocolitis (NEC), which is credible. However, some other studies have not found any benefits from this process.

　　Necrotizing enterocolitis can occur in neonatal intensive care units in clusters or outbreaks; epidemiological studies have confirmed that some clusters are associated with specific pathogens (such as Klebsiella, Escherichia coli, and coagulase-negative staphylococci), but special pathogens are usually not found.

　　1. Blood count shows a significant decrease in granulocytes, which may be less than 0.5×109/L. If the primary disease is aplastic anemia, there will be a significant decrease in all blood cells.

　　2. Blood tests are performed to check blood pH and levels of sodium, potassium, and chloride.

　　3. The fecal examination may show abnormal changes such as blood in the stool.

　　Nutritional Diet Principles

　　1. Low-sodium Diet

　　Only 3-5 grams of salt can be used daily. Daily diet should choose foods with low sodium content, such as beans and bean products, vegetables, fruits, etc.

　　2. Eating Foods High in Potassium

　　High-potassium foods include fresh mushrooms, cucumbers, oranges, sweet corn, glutinous rice, potatoes, longans, grapes, coconuts, persimmons, watermelons, mangoes, etc.

　　3. Eating More Alkaline Foods

　　Alkaline foods include beans, vegetables, fruits, chestnuts, lilies, milk, lotus root, egg white, kelp, tea, etc.

　　4. High-protein Diet

　　High-protein foods include soybeans, broad beans, peas, peanuts, beef, pork, chicken, duck meat, internal organs, eggs, milk powder, etc.

　　I. Treatment

　　1. Internal Medicine Treatment

　　Fasting, fluid replacement, correction of water and electrolyte imbalance, application of sensitive broad-spectrum antibiotics, transfusion of blood products, intravenous hyperalimentation, etc. Antibiotics should be首选 for intestinal bacilli, and it is advisable to use two or more antibiotics together. If fungal infection is suspected, antifungal antibiotics should be used promptly. In cases with low blood pressure and circulatory disorders, active anti-shock treatment should be carried out. The transfusion of granulocytes is unlikely to increase peripheral blood granulocyte levels and may not be effective for treating infection. Moreover, it is expensive and may have other complications, so it cannot be used as a routine therapy.

　　2. Surgical Treatment

　　It is generally recommended to avoid surgical exploration and partial resection of the intestinal segments as much as possible. Indications for surgery are:

　　(1) Persistent gastrointestinal bleeding: after correcting coagulation abnormalities, platelets and granulocytes are gradually recovering, but there is still persistent gastrointestinal bleeding.

　　(2) Intestinal perforation: clinical manifestations and physical examination suggest intestinal perforation.

　　(3) Gradual deterioration of clinical condition: during the process of internal medicine treatment, the clinical condition gradually worsens, and vasoconstrictors and a large amount of fluid replacement are needed to maintain circulation, or sepsis is not controlled.

　　(4) Progression of intra-abdominal lesions: granulocytes return to normal, while there is progression of intra-abdominal lesions.

　　The treatment of this symptom often requires close cooperation between internal and external medicine doctors and careful observation of the course of the disease. Strong chemotherapy should be suspended during the treatment period.

　　II. Prognosis

　　The prognosis of this symptom depends on the etiology. Patients with complications have a higher mortality rate.