Ulcerative colitis

　　The etiology of ulcerative colitis is still unclear. Genetic factors may play a certain role. Psychological factors are important in the progression of the disease, and pathological mental states such as depression or social isolation may improve significantly after colectomy. Some believe that ulcerative colitis is an autoimmune disease. Currently, it is believed that the onset of inflammatory bowel disease is the result of the interaction among exogenous substances causing host reactions, genetic, and immune influences.

　　1. Toxic megacolon
　　Severe complications occur in patients with acute fulminant ulcerative colitis and acute severe type, with an incidence of about 2%. Patients may experience intermittent high fever, debilitation, and a severe toxic state. The abdomen swells rapidly, with tenderness, and bowel sounds become weakened or disappear. Due to rapid expansion of the colon, thinning of the intestinal wall, impaired blood supply, and the risk of intestinal necrosis and perforation, the mortality rate is extremely high, reaching 30% to 50%.

　　2. Colonic perforation
　　It often occurs on the basis of toxic megacolon expansion. Perforation leads to diffuse peritonitis or localized abscess. The perforation site is often at the sigmoid colon or splenic flexure of the colon. Patients often present with high fever and symptoms of infection and intoxication, abdominal distension, widespread muscle tension in the left lower abdomen, and free gas under the diaphragm is often found in X-ray透视 or flat film examination.

　　3. Lower gastrointestinal bleeding
　　The rectum and colon can bleed extensively. The majority of cases manifest as hematochezia and purulent stool.

　　4. Rectal and colonic cancer
　　The incidence of malignancy is 0.7% to 8%, even up to 13%. It is 5 to 20 times higher than the general population. The course of the disease is more than 10 years.

　　5. Rectal and colonic strangulation
　　It is a late complication, but it rarely causes intestinal obstruction.

　　6. Internal fistula
　　Intestinal cavities may adhere to each other or to other hollow organs (such as the bladder, vagina, etc.) to form internal fistulas; intestinal cavities may communicate with the skin to form external fistulas, which occur occasionally.

　　7. Anal and perianal diseases
　　Such as anal fissure, perirectal abscess, anal fistula, hemorrhoids prolapse, and others.

　　8. Other systemic complications
　　Such as non-specific arthritis, nodular erythema, gangrenous pyoderma, iritis, iridocyclitis, keratitis, stomatitis, and parotitis, as well as fatty liver, pericholangitis, and others.

　　The initial manifestations of ulcerative colitis can take many forms. Bloody diarrhea is the most common early symptom. Other symptoms include abdominal pain, hematochezia, weight loss, tenesmus, vomiting, and others. Occasionally, the main manifestation may be arthritis, iridocyclitis, liver dysfunction, and skin lesions. Fever is relatively uncommon, and in most patients, the disease manifests as chronic and low malignant; in a few patients (about 15%) it presents as an acute, catastrophic outbreak. These patients may have bloody stools, up to 30 times a day, high fever, and abdominal pain.

　　Signs and symptoms are directly related to the course of the disease and clinical manifestations. Patients often have weight loss and pale complexion, and during abdominal examination during the active phase of the disease, the colon area often has tenderness. There may be signs of acute abdomen accompanied by fever and decreased bowel sounds, especially in acute onset or fulminant cases. Toxic megacolon may present with abdominal distension, fever, and signs of acute abdomen. Due to frequent diarrhea, the perianal skin may have abrasions and desquamation. Perianal inflammation such as anal fissure or fistula may also occur, although the latter is more common in Crohn's disease. Rectal examination may be painful. Examination of the skin, mucous membranes, tongue, joints, and eyes is extremely important.

　　1. Pay attention to the combination of work and rest, do not overwork; patients with fulminant, acute onset, and severe chronic type should rest in bed.
　　2. Pay attention to clothing, maintain appropriate warmth and cold; appropriately engage in physical exercise to enhance physical fitness.
　　3. Generally, soft, easily digestible, nutritious, and sufficient in calories food should be eaten. It is advisable to eat small meals frequently and supplement with various vitamins. Avoid eating raw, cold, greasy, and high-fiber foods.
　　4. Pay attention to food hygiene to avoid intestinal infections that may trigger or worsen the disease. Avoid smoking, alcohol, spicy foods, milk, and dairy products.
　　5. Maintain a pleasant mood in daily life, avoid mental stimulation, and relieve various mental stresses.

　　Diagnosis mainly relies on colonoscopy, because 90% to 95% of patients are affected by the rectum and sigmoid colon, so in fact, a diagnosis can be made by fiberoptic sigmoidoscopy. During the examination, you can see congested, edematous mucosa that is fragile and prone to bleeding. In progressive cases, you can see elevated granulation tissue around ulcers and edematous mucosa, resembling polyps, or it can be called pseudopolyp formation. In chronic progressive cases, the rectum and sigmoid colon lumen can become significantly smaller. To clarify the extent of the lesion, fiberoptic colonoscopy should be used for a full colon examination, and multiple biopsies should be performed to distinguish from Crohn's colitis.

　　Barium enema double-contrast imaging is also a helpful diagnostic examination, especially helpful in determining the extent and severity of the lesion. In barium enema, the disappearance of colonic pouches, irregular colonic wall, formation of pseudopolyps, and narrowing and rigidity of the intestinal lumen can be seen. Although barium enema examination is valuable, it should be done cautiously to avoid intestinal cleaning preparation, as it can worsen colitis. For cases without diarrhea, a 3-day liquid diet can be given before the examination. For cases with abdominal signs, barium enema examination should be avoided, and abdominal X-ray films should be taken to observe for signs of toxic megacolon, colon dilation, and free gas under the diaphragm.

　　1. Pay attention to a light diet, and easily digestible and absorbable foods such as vegetable porridge and noodle soup are preferred.
　　2. You can eat more fresh fruits and vegetables to ensure the intake of vitamins.
　　3. Provide liquid or semi-liquid foods, such as various porridge, rice soup, etc.

　　1. Medical treatment
　　(1) Bed rest and general supportive treatment include fluid and electrolyte balance, especially potassium supplementation, and those with hypokalemia should be corrected. At the same time, attention should be paid to protein supplementation, improving the overall nutritional status, and providing parenteral nutrition support when necessary. Those with anemia can receive blood transfusions, and milk and dairy products should be avoided as much as possible during gastrointestinal intake.
　　(2) Drug therapy: ①Salicylate preparations of sulfasalazine are the main therapeutic drugs, such as Edissa and Mesalazine. ②Commonly used corticosteroids include prednisone or dexamethasone, but it is not currently believed that long-term hormone maintenance can prevent recurrence. During the acute attack phase, hydrocortisone or dexamethasone can also be administered intravenously, and hydrocortisone can be added to normal saline for retention enema every night. The value of hormone treatment during the acute attack phase is confirmed, but whether to continue using hormones during the chronic phase is still controversial, as it has certain side effects, so most do not advocate long-term use. ③The value of immunosuppressants in ulcerative colitis is still questionable. According to reports by Rosenberg et al., azathioprine has no effect on controlling the disease during disease deterioration, but it can help reduce the use of corticosteroids in chronic cases. ④Traditional Chinese medicine treatment for diarrhea-type ulcerative colitis can be treated with traditional Chinese medicine, and the effect is relatively ideal.
　　2. Surgical Treatment
　　20% to 30% of severe ulcerative colitis patients eventually undergo surgical treatment.
　　(1) Indications for Surgery The indications for emergency surgery include: ① Large, uncontrollable bleeding; ② Toxic megacolon with adjacent or definite perforation, or toxic megacolon that is ineffective after several hours of treatment instead of several days; ③ Acute ulcerative colitis that is refractory to corticosteroid hormone treatment, that is, there is no improvement after 4 to 5 days of treatment; ④ Obstruction caused by stricture; ⑤ Suspicion or confirmation of colon cancer; ⑥ Recurrent and worsening refractory ulcerative colitis with chronic persistent symptoms, malnutrition, weakness, inability to work, and inability to participate in normal social activities and sexual life; ⑦ When the dose of corticosteroid hormones is reduced, the disease worsens, resulting in the inability to stop hormone treatment for several months or even years; ⑧ Children with chronic colitis that affects their growth and development; ⑨ Severe extracolonic manifestations such as arthritis, necrotizing pyoderma, or biliary liver diseases, etc., surgery may be effective for them.
　　(2) Surgical Options There are currently four surgical options for ulcerative colitis: ① Total colectomy and ileostomy; ② Total colectomy and ileorectal anastomosis; ③ Controlled ileostomy; ④ Total colectomy and ileorectal pouch-anal canal anastomosis.
　　Currently, there is no effective long-term prevention or treatment method. Among the existing four types of surgery, total colectomy and ileorectal anastomosis is a relatively reasonable and selectable option.