Ulcerative colitis is the abbreviation for chronic nonspecific ulcerative colitis, a chronic inflammatory disease of the rectum and colon of unknown origin. The main clinical manifestations are diarrhea, mucopurulent stools, abdominal pain and urgency. The disease varies in severity and is recurrent or prolonged with a chronic course. The disease can occur at any age, with 20-50 years old being the most common. There is no significant difference in the incidence between men and women. The disease is more common in Europe and the United States, but the incidence in China is low, and the disease is generally mild.
Etiology and pathogenesis
The cause of the disease has not been completely elucidated. It is believed that the onset of the disease may be related to the following factors.
1, autoimmune
The disease is mostly complicated by autoimmune extraintestinal manifestations such as erythema nodosum, arthritis, uveitis, iritis, etc. Adrenocorticosteroid treatment can make the disease remit, and anti-colonial epithelial cell antibodies can be detected in the serum of some patients, so it is believed that the occurrence of the disease and autoimmune reactions may be related.
2.Pathological reaction
There is information that during the active period of ulcerative colitis, the mast cells of the intestinal wall increase, and the cells are stimulated to release a large amount of histamine, resulting in intestinal wall congestion, edema, smooth muscle spasm, mucosal erosion and ulceration, which is related to the acute onset or sudden relapse, is a rapid hypersensitivity reaction, and this allergic reaction of the intestinal wall may be a local manifestation of the disease.
3. Heredity
The incidence of this disease is high in the blood family, about 5-15% of the relatives of patients have this disease, and there are significant differences in the incidence between races, suggesting that genetic factors play a role in the development.
4.Infection
The pathological changes and clinical manifestations of this disease are similar to those of infectious diseases of the colon, such as bacillary dysentery. Therefore, infection has long been considered as the cause of the disease, but so far it has not been possible to identify the causative bacteria, viruses or fungi.
5.Neuropsychiatric factors
It has been suggested that mental depression and anxiety may be related to the occurrence and recurrence of the disease, but recent clinical data indicate that the disease is not more common in people with a history of mental abnormalities or trauma than in the general population.
In short, the occurrence of the disease may be the result of the interaction between immune, genetic and other factors and exogenous stimuli.
Pathology
The lesions first involve the rectum and sigmoid colon, but may also extend to the descending colon, transverse colon, and occasionally to the entire colon and occasionally to the unsegmented ileum. The lesions are diffuse and continuous in nature. The mucosa is extensively congested, edematous, erosive and hemorrhagic, and microscopic examination reveals lymphocytes, plasma cells, eosinophils and neutrophils infiltrating the mucosa and submucosa. Microscopic abscesses form at the base of the intestinal glands in the crypt, and these crypt abscesses may fuse with each other and break down, resulting in extensive, irregular, small superficial ulcers with surrounding mucosal hemorrhage and diffuse inflammation. With the development of the disease, the above ulcers can develop along the longitudinal axis of the colon and fuse to form irregular large ulcers, but because the colon lesions are generally limited to the mucosa and submucosa and rarely reach the muscular layer, it is uncommon to have ulcer perforation, fistula formation or peri-colonic abscesses, and in a few severe or violent cases, the lesions involve the whole colon and toxic megacolon can occur. If the ulcer expands deep into the muscular layer and plasma layer, ulcer perforation, peritonitis, peri-colonic or rectal abscess, and fistula formation may occur.
The repeated attacks of this disease lead to the proliferation of granulation tissue and the formation of polyp-like protrusions of the mucosa, called pseudopolyps, or the formation of scarring after the ulcer heals and the proliferation of fibrous tissue, resulting in thickening of the intestinal wall, deformation and shortening of the colon, and narrowing of the intestinal lumen. In a few cases, it can become cancerous.
Clinical manifestations
The onset of the disease is mostly slow, with a few acute onset. The course of the disease is chronic, several years to more than ten years, often with recurrent attacks or continuous aggravation, and occasionally with acute fulminant process. Mental stimulation, exertion and eating disorders are often the triggers for the development of the disease.
1.Digestive system performance
(1) Diarrhea
It is caused by increased intestinal peristalsis and impaired absorption of water and sodium in the intestinal lumen due to inflammatory stimulation. The degree of diarrhea varies from 3-4 times a day in mild cases, or alternating diarrhea and constipation; in severe cases, the number of bowel movements can be as many as 30 times a day, with mucus, pus and blood, and the lesions involving the rectum are followed by urgency.
(2) Abdominal pain
Mild type and lesions in remission may have no abdominal pain, or mild to moderate vague pain, a few colic, mostly confined to the left lower abdomen and lower abdomen, or total abdominal pain. The nature of the pain is often spasmodic, with a pattern of pain followed by bowel movements and relief after bowel movements, often accompanied by abdominal distension.
(3) Other symptoms
In severe cases, there may be loss of appetite, nausea and vomiting.
(4) Signs: Light patients have light pressure pain in the left lower abdomen, and some patients may palpate the spastic or thickened sigmoid or descending colon of the intestinal wall. In severe and fulminant cases, there may be obvious bulging bowel, abdominal muscle tension, abdominal pressure pain and rebound pain.
2. Systemic manifestations
There is often low or moderate fever during the acute phase or acute attack, and in severe cases, there may be high fever and tachycardia, and there may be wasting, weakness, anemia, imbalance of water and electrolyte balance and malnutrition during the development of the disease.
3.Extra-intestinal manifestations
There are often nodular erythema, arthritis, uveitis, oral mucosal ulcers, chronic active hepatitis, hemolytic anemia and other abnormal changes of immune status.
Complications
1. Toxic megacolon
Toxic megacolon can occur when ulcerative colitis is extensive and severe, and involves the muscular layer and the enteromyocardial plexus. Foreign reports are seen in 15% of patients, but it is rare in China. The common triggers are massive application of anticholinergic drugs, narcotics and hypokalemia. The clinical presentation is a rapid deterioration of the disease. Toxemia is evident with enlargement of the colonic lumen, causing acute colonic dilatation, bulging bowel, abdominal pressure pain, and loss of bowel sounds. The prognosis of this complication is very poor. It is easy to cause acute intestinal perforation, acute diffuse peritonitis, etc.
2.Colon cancer
Overseas reports about 5-10% of this disease carcinoma, the domestic incidence is low. Carcinoma mainly occurs in heavy cases, the lesions involve the whole colon and patients with a long course of disease.
3.Colonic haemorrhage
The incidence is about 3%, mostly seen in severe and fulminant cases.
Laboratory and other tests
1.Blood test
There may be mild to moderate anemia, and in severe cases, the white blood cell count is increased and the erythrocyte sedimentation rate is accelerated. An increase in serum a2 globulin and a decrease in r globulin during remission is often a precursor to relapse.
2.Fecal examination
There is mucopurulent stool in the active phase. Repeated examinations including routine, culture and incubation are not found for specific pathogens, such as amebic cysts and schistosome eggs.
3.Immunological examination
IgG and IgM may be slightly increased, anti-colonic mucosal antibodies are positive, the ratio of T lymphocytes to B lymphocytes is decreased, and the total serum complement activity (CH50) is increased.
4.Fiber colonoscopy
It is the most valuable diagnostic method, and the nature of the lesion can be clarified through colonic mucosal biopsy. Microscopic examination shows diffuse congestion, edema, coarse or finely granular mucosa, fragile mucosa, easy bleeding, adherence of mucus, blood, purulent secretions, and multiple erosions, shallow small ulcers, and in severe cases, the ulcers are large and can be fused into sheets with irregular edges.
5.Barium enema X-ray examination
It is an important diagnostic method. In the acute stage of the disease, the intestinal mucosa is congested and edematous, and the folds are coarse and disorganized; when there are ulcers and secretions, the edges of the intestinal wall can be burr-like or jagged, and in the later stage, the fibrous tissue of the intestinal wall proliferates, the colonic pouch disappears, the intestinal wall becomes hard, the intestinal lumen shortens and narrows, and it can be in the shape of a lead tube.
Diagnosis and differential diagnosis
Based on chronic abdominal pain, diarrhea, mucopurulent and bloody stools. Repeated stool examination without pathogens should be considered for this disease, and further barium enema X-ray and colonoscopy should be performed to help confirm the diagnosis. This disease should be differentiated from the following diseases.
1.Chronic bacillary dysentery
Often have a history of acute bacillary dysentery, stool and colonoscopy to take mucopurulent secretions culture Bacillus dysenteriae positive rate is high, antibacterial drug treatment is effective.
2.Amoebic dysentery
Stool examination can find amoebic trophozoites or encapsulation. Colonoscopy ulcers are deeper, the edges are submerged, the colonic mucosa between ulcers is normal, biopsy or microscopic examination of exudate taken from the ulcer can find amebic cysts or trophozoites. Anti-amoebic treatment is effective.
3.Colon cancer of the rectum
Cancer occurring in the rectum can be palpated by anal finger examination, and biopsy by fiberoptic colonoscopy and barium enema examination is valuable for differential diagnosis.
4.Differentiation of ulcerative colitis and clonorchiasis
See clonorchiasis.
5.Schistosomiasis
History of exposure to epidemic water, hepatomegaly, fecal examination can find schistosome eggs, positive hatching trichurias, colonoscopy can be seen in the intestinal mucosa with yellow granular nodules, intestinal mucosa biopsy can find schistosome eggs.
6.Intestinal irritation syndrome
It is caused by colonic dysfunction. There may be a lot of mucus in the stool but no pus and blood, often accompanied by neurosis, no organic lesions on X-ray barium enema and colonoscopy.
Treatment
In recent years, we mainly adopt comprehensive internal medicine treatment to control acute attacks, reduce recurrence and prevent complications.
1.General treatment
Acute attacks, especially heavy and fulminant cases should be hospitalized, timely correction of water and electrolyte balance disorders, if there is significant malnutrition hypoproteinemia can be transfused with whole blood or serum albumin. Heavy cases should be fasted, given intravenous high nutrition therapy, and given liquid diet or easy to digest, less fiber, rich nutrition diet as appropriate after the condition improves. If the abdominal pain is obvious, small doses of antispasmodics such as atropine and prulbenecid can be given, but should prevent the induction of toxic megacolon.
2.Azo sulfonamides with water
Generally, azo sulfadiazine pyridine with water (referred to as SASP) is the drug of choice for light or heavy patients who have been relieved by adrenal glucocorticosteroid treatment, and the efficacy is good. The drug is broken down in the colon by enterobacteria into 5-aminosalicylic acid (5-ASA) and sulfapyridine, the former being the main effective ingredient to eliminate inflammation. The dosing method is 4-6g per day in 4 oral doses during the exacerbation period and then changed to 2g per day in oral doses for 1-2 years after the remission of the disease. It is also advocated that the above maintenance dose should be used for 2 weeks and stopped for 1 week, and so on alternately for 1-2 years to prevent relapse. The side effects of sulfonamide such as nausea, vomiting, skin rash, leukopenia and hemolytic reaction should be observed during the dosing period.
3.Adrenal glucocorticoid
It can control inflammation, suppress autoimmune process and reduce the symptoms of poisoning, and has good effect. Commonly used hydrocortisone 200-300mg, or dexamethasone 10mg daily intravenous drip, the course of treatment 7-10 days, after the alleviation of symptoms, change to prednisolone, 40-60mg daily, divided into 4 times orally, after the disease control, decreasing the amount of drugs, after stopping the drug can be given salicylate azosulfapyridine After discontinuation, azosulfapyridine salicylate can be given.
4. Azathioprine
It is an immunosuppressant, suitable for chronic and recurrent patients, or those who are not treated with sulfonamide and hormone. It is administered as 1.5 mg per kg of body weight per day, orally in divided doses, for a period of 1 year. Side effects are mainly bone marrow suppression and concurrent infections.
5.Antibiotics
For fulminant and heavy cases to control secondary infection, use gentamicin, ampicillin, methotrexate and other treatments.
6.Enema treatment
Suitable for patients with mild lesions limited to the rectum and left colon. Commonly used hydrocortisone 100mg dissolved in 0.25% procaine solution 100ml, or Ringer’s solution 100ml reserved enema, once a day, the course of treatment 1-2 months. Alternatively, sodium hydrocortisone succinate 100 mg and dexamethasone 5 mg in 100 ml of saline retention enema can be used. Or add SASP 1-2g enema, but SASP enema solution is unstable and must be freshly prepared before use. In addition, there are reports of the efficacy of enemas with Chinese medicine.
7.Surgical treatment
Complicated carcinoma, intestinal perforation, abscess and fistula, toxic megacolon is the indications for surgery after medical treatment is ineffective. Generally, total colectomy or ileostomy is performed.