Colon distention

Introduction Ulcerative colitis (UC), referred to as ulceration, an unexplained rectal or colonic inflammatory disease. Mainly involving the rectum, sigmoid colon and descending colon, pathological features of mucosal congestion, edema, multiple superficial ulcers, advanced intestinal wall thickening, intestinal stenosis and associated with polyps. Clinically, it is characterized by intractable diarrhea, mucus, bloody stool or pus and bloody stool, abdominal pain and urgency. It can be accompanied by parenteral manifestations such as fever, anemia, arthritis, skin lesions and liver disease. Very few acute onset, most of the onset is slow, the course of disease is longer, often recurrent, and the period of reversal is also called chronic non-specific ulcerative colitis. Abdominal pain, diarrhea, and bloody stools can occur early. Different degrees of abdominal pain are caused by colonic muscle spasm, colonic swelling and inflammation stimulating local sensory nerves. Abdominal distension is mostly confined to the left lower abdomen or lower abdomen, showing paroxysmal mild pain. Colic can be present when the lesion is severe.

Cause

Etiology and pathogenesis

It is now completely clear and may be related to factors such as immunity, genetics, spirit and infection.

In the course of development, the disease is often accompanied by autoimmune diseases such as hemolytic anemia, arthritis, nodular erythema, liver disease, etc., and the condition can be alleviated after treatment with adrenocortical hormone. Anti-colon epithelial antibody and anti-E. coli O14 antibody were found in the serum of some patients, and these antibodies reacted autoimmunely with colonic epithelial antigen to cause mucosal damage. There is lymphocyte infiltration in the colon tissue of the lesion, and in the tissue culture, the lymphocytes of the patient are found to have a cytotoxic effect on normal human colonic epithelial cells. Fluorescence immunoassay confirmed the presence of immune complexes of IgG, complement and fibrinogen deposition in the lamina propria of the colonic mucosa. This immune complex was found to have a detrimental effect on the colonic mucosa. This indicates that the pathogenesis of this disease is related to the immune response, so it is considered to be an autoimmune disease.

The disease is often familial, the incidence rate in the family of patients is significantly increased, and the incidence rate among ethnic groups is also significantly different. The incidence rate in Europe and the United States is significantly higher than that in Asian countries such as Japan, which suggests that the incidence may be related to genetic factors. In addition, the number of human leukocyte antigens HLA-11 and 7 in patients with this disease increased, suggesting that genetic factors may have a status in the pathogenesis. Mental factors and emotional changes cause autonomic dysfunction, leading to inflammation of the intestinal wall and promoting the onset of the disease. It is generally considered to be a predisposing factor for the onset of the disease. The pathological changes and clinical manifestations of this disease are similar to those of bacterial dysentery, but failure to find possible pathogens in the feces. Some people think that dysentery bacilli, intestinal bacteria and viral infections may be related to the pathogenesis of this disease, but it is only a predisposing factor.

pathology

Most of the lesions occur in the rectum and sigmoid colon, and can also affect the descending colon or the entire colon, involving the end of the ileum. In the early stage, the colonic mucosa was characterized by edema, congestion, hemorrhage, and granules. Thereafter, irregular small ulcers are formed, which in turn merge into irregular large ulcers. A large amount of scar formation during ulcer healing can lead to shortening of the colon and narrowing of the intestinal lumen, and the formation of inflammatory polyps on the mucosal surface ("pseudopolyps"). Inflammatory lesions of ulcerative colitis are confined to the mucosal layer or extend to the submucosal layer, less deeply reaching the muscular layer. The lesion develops from the distal end of the large intestine to the proximal end, showing a continuous distribution, but occasionally a segmental distribution. At this time, attention should be paid to the differentiation of localized enteritis.

an examination

Related inspection

Colonoscopy fiberoptic colonoscopy for tumor necrosis factor alpha

1. Type can be divided into 4 types according to clinical manifestations and processes.

(1) Initial hair style: Symptoms vary in severity, and there is no history of ulceration, which can be converted into chronic recurrent or chronic persistent type.

(2) Chronic recurrence type: The symptoms are mild, the most common in clinical practice, and there are often remission periods of different lengths after treatment. The peak of recurrence is mostly in spring and autumn, but less in summer. Colonoscopy in the onset of the colon, there are typical ulceration lesions, while the remission period only see mild congestion, edema, mucosal biopsy is chronic inflammation, easy to be mistaken for irritable bowel syndrome. Some patients can be converted to chronic persistent.

(3) Chronic persistent type: After the onset, there are often diarrhea, intermittent bloody stools, abdominal pain and systemic symptoms ranging from several weeks to several years, during which there may be an acute attack. This type of lesion has a wide range of lesions, and the colonic lesions are progressive, with many complications. The symptoms are severe in acute attacks and require surgical treatment.

(4) Acute fulminant: Domestic reports are few, accounting for 2.6% of the collapse, and foreign reports account for 20%. More common in adolescents, rapid onset, systemic and local symptoms are severe, high fever, diarrhea 20 to 30 times a day, blood in the stool, can cause anemia, dehydration and electrolyte imbalance, hypoproteinemia, weakness and weight loss, and easy to occur Toxic colonic dilatation, intestinal perforation and peritonitis often require urgent surgery and high mortality.

2. The main symptoms of diarrhea or constipation, the symptoms at the beginning of the disease is lighter, there is mucus on the surface of the feces, and then increase later, the severe defecation 10 to 30 times a day, the feces often mixed with pus and mucus, can be a paste-like soft stool. Blood in the stool is a more common symptom, mainly due to the increase of colonic mucosal ischemia and fibrinolytic activity. Generally, it is a small amount of blood in the stool. In severe cases, it can be a large amount of blood in the stool or bloody stool. Abdominal pain is limited to the left lower abdomen or lower abdomen. Patients with mild disease may also have no abdominal pain. The abdominal pain will increase with the development of the disease, and it can be relieved after defecation. After the urgency, the heavy system is caused by inflammation and stimulates the rectum, and often has an ankle discomfort. Indigestion often shows anorexia, fullness, belching, upper abdominal discomfort, nausea, vomiting and so on. Systemic performance is more common in patients with acute fulminant dysentery, fever, water and electrolyte imbalance, vitamins, protein loss, anemia, weight loss and so on.

3. Signs of left lower abdomen or total abdominal tenderness, can be sputum and descending colon, especially the sigmoid colon is hard tubular, and there is tenderness, sometimes abdominal muscle tension, anal sphincter spasm can be found in the anus, mucus or bloody mucus secretions, rectum It is tender. Some people can touch the liver, which is related to fatty liver.

diagnosis

1. Diagnostic criteria. Because ulcerative colitis is a non-specific inflammatory disease, its clinical manifestations are diverse, and it is difficult to find typical clinical features for diagnosis. In 1993, the National Symposium on Chronic Non-infectious Enteric Diseases was held in China, according to international diagnosis. The standard sets the diagnostic criteria for ulcerative colitis in combination with the specific situation in China:

1 to exclude bacterial dysentery, amebic colitis, schistosomiasis, intestinal tuberculosis, Crohn's disease, radiation enteritis and other reasons for colonic inflammation;

2 has typical clinical manifestations, and at least one of the characteristic changes of endoscopy or X-ray; 3 clinical symptoms are atypical, but with typical colonoscopy or X-ray findings or confirmed by pathological biopsy.

2. Severity judgment. Truelove and Witts classify ulcerative colitis into light, medium, and heavy types based on clinical manifestations and laboratory measurements. This assessment helps clinicians estimate the condition and provide a basis for treatment.

Differential diagnosis

1 chronic bacterial dysentery:

There is often a history of acute bacillary dysentery, and faecal culture can isolate dysentery bacilli. The positive rate of mucus purulent secretion culture during colonoscopy is higher, and antibacterial therapy is effective.

2 chronic amoebic dysentery: the lesion mainly invades the right colon, but also can affect the left colon, the colon ulcer is deep, the edge is sneak, and the mucosa between the ulcers is mostly normal. Fecal examination can be found in the amoeba trophozoites or cysts in the lysate, and it is easier to find the amoebic trophozoites by taking the ulcer exudate from the colonoscope for intestinal examination. Anti-amebic treatment is effective.

3 colon cancer: more common in middle-aged, often through the rectal examination can touch the mass, colonoscopy and X-ray barium enema examination is valuable for differential diagnosis, attention should be paid to the difference between colon cancer caused by ulcerative colitis.

4 schistosomiasis: history of contact with infected water, often hepatosplenomegaly, fecal examination can be found schistosomiasis eggs, hatching hairy sputum, rectal examination in the acute phase visible mucosa yellow brown granules, biopsy mucosa tablets or histopathological examination found schistosomiasis egg.

5 irritable bowel syndrome: with systemic neurosis, mucus in the stool but no pus, microscopic examination only a few white blood cells, colonoscopy without evidence of organic lesions.

6 other: intestinal tuberculosis, ischemic colitis, pseudomembranous colitis, Clostridium difficile enteritis, radiation enteritis, colon polyposis, colonic diverticulitis, etc. should be differentiated from the disease.

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