Ischemic colitis

　　The onset time of left upper quadrant abdominal pain in patients with this disease is often about 1 hour after meals, which can be self-relieved. The possible cause may be that after meals, a large amount of blood in the human body concentrates in the upper gastrointestinal tract, causing the blood supply to the colon, which was already insufficient, to become even less or absolutely insufficient, leading to acute ischemic necrosis of the colonic mucosa.

　　Clinical situations that are prone to trigger the disease include the following:

　　1. Elderly with heart failure due to hypertension, arteriosclerosis, or coronary heart disease.

　　2. Abuse of diuretics leading to reduced visceral blood flow.

　　3. Long-term constipation or persistent colonic spasm leading to increased intraluminal pressure.

　　4. Use of certain vasoactive drugs leading to constriction of mesenteric small arteries.

　　5. Some vascular diseases, such as thrombotic arteritis, connective tissue disease, etc.

　　Patients often have a history of hypertension, arteriosclerosis, heart disease, and long-term medication. The main complications of ischemic colitis include the following two types.

　　1. Intestinal obstruction: In the early stage of gangrenous ischemic colitis, extensive lesions may cause paralytic ileus due to severe acute ischemia of the colon; in chronic ischemic colitis, due to fibrous tissue proliferation and scar formation during the chronic inflammatory process, the intestinal lumen may become narrow, leading to incomplete intestinal obstruction.

　　2. Shock: In the early stage of gangrenous ischemic colitis, due to the large absorption of necrotic tissue and bacterial toxins, the microcirculatory vessels are widely open, the effective blood volume is insufficient, and the patient may develop hypovolemic and/or toxic shock.

　　The clinical manifestations of this disease are mainly three syndromes: prominent abdominal pain, diarrhea, and hematochezia. The onset age is mostly over 50 years old.

　　Ischemic colitis mainly has the following three types.

　　1. Transient colitis type: Patients may suddenly develop symptoms, with pain in the middle, lower abdomen, or left lower abdomen, followed by diarrhea and hematochezia. Abdominal tenderness and muscle tension may occur, and symptoms may disappear within a few days without recurrence.

　　2. Stricture type: Patients may experience recurrent episodes of abdominal pain, constipation, diarrhea, and hematochezia, which often resolve spontaneously. Obstruction may occur when the intestinal stricture is severe.

　　3. Gangrenous type: This type is rare, mostly affecting the elderly, with sudden onset, rapid expansion of abdominal pain to the whole abdomen, signs of peritonitis, and early shock. The prognosis is poor.

　　The onset age of ischemic colitis is mostly over 50 years old, so the elderly should pay more attention to regular lifestyle, avoid smoking and alcohol, eat more vegetables and fruits rich in vitamins, and try to avoid eating high-fat foods such as fatty meat and animal internal organs. In addition, they should moderately participate in some indoor and outdoor sports.

　　The main examination methods for ischemic colitis include the following.

　　1. Barium enema X-ray examination: The most significant sign in the acute phase is pressure sign and rough, irregular mucosa, limited colonic spasm, and disappearance of colonic valvulae.

　　2. Selective angiography: Angiography can determine the location, extent, and degree of arterial stenosis.

　　3. Fiberoptic colonoscopy: It is not advisable to perform colonoscopy for hemorrhagic necrotic patients.

　　In terms of diet, the following points should be noted for ischemic colitis:

　　1. Diet should be easy to digest, soft with little residue, and non-irritating foods are preferred.Low-fiber foods can reduce intestinal peristalsis and alleviate diarrhea. Foods such as eggs, thin noodles, rice porridge can be eaten. Foods rich in roughage should be eaten as little as possible.

　　2. Eat more foods that have astringent effects on diarrhea.Foods such as purslane, Job's tears, mung beans, yam, hawthorn, black plum, apple, lychee, lotus seeds, glutinous rice, sticky rice, ham, and black chicken can reduce diarrhea.

　　3. Appropriately control fat intake.Avoid eating high-fat foods and fried foods in the diet. Cooking should use less oil and adopt methods such as steaming, braising, and stewing. Avoid eating high-fat foods such as lard, mutton fat, butter, beef fat, and walnuts, as this may worsen diarrhea.

　　4. Avoid eating gas-producing foods.Foods such as soybeans, soy products, fried broad beans, sweet potatoes, etc., which cause gas, can lead to intestinal gas accumulation and complications such as acute intestinal dilatation or ulcer perforation.

　　5. Avoid eating raw fruits and vegetables.Most patients with this disease have weak spleen and stomach, and weak kidney yang. Eating cold and raw fruits and vegetables can further damage the spleen and kidney yang, causing the movement of the spleen and stomach to become weak and internal cold and dampness to accumulate. In addition, these foods are naturally slippery, which can worsen diarrhea and abdominal pain.

　　6. Avoid eating milk and seafood.Diarrhea patients are prone to develop colonic allergies after consuming milk, condensed milk, shrimp, seafood, etc., which can lead to exacerbation of diarrhea.

　　In the treatment of this disease, attention should be paid to the following points:

　　1. The main treatment for this disease should be to treat the primary disease. If the heart function is normal, drugs that cause mesenteric vascular constriction, such as digitalis and vasopressin, should be discontinued as much as possible.

　　2. For middle-aged and elderly patients without clear contraindications to drug use, drugs that improve microcirculation, such as Danshen tablets, can be administered. In addition, for patients with severe intestinal dysfunction, active symptomatic treatment should be provided. For patients with colon distension, intestinal gas exhaust decompression and nasal feeding tube aspiration decompression should be provided; for those with nausea and vomiting, antiemetic and gastrointestinal motility drugs should be administered; for diarrhea patients, intestinal mucosal protective agents such as Simida and bismuth subcarbonate can be administered. Steroids are not helpful for the recovery of ischemic lesions and may promote intestinal perforation, so it is not recommended to use them.

　　3. Most patients can recover quickly after internal medicine treatment, but a small number of patients may have their condition worsen and develop intestinal necrosis. At this time, emergency surgery should be performed to remove the necrotic intestinal segment early.