1.What is ulcerative colitis?
Ulcerative colitis (UC) is a chronic non-specific inflammatory disease of the rectum and colon whose etiology is not well understood. The lesions are mainly confined to the mucosa and submucosa of the large intestine; the extent of the disease is mostly distal to the colon, and the lesions may progress retrogradely to the proximal segment and even involve the whole colon and the terminal ileum. The clinical manifestations are diarrhea, mucopurulent stools, and abdominal pain. The disease varies in severity and has a chronic course with recurrent episodes. The disease can occur at any age, mostly in 20-40 years old, but also in children or the elderly. There is no significant difference in the incidence between men and women. The disease is less common in China than in Europe and the United States, and the disease is generally mild, but the prevalence seems to have increased in recent years, and severe cases have been reported.
2. What are the signs and symptoms of ulcerative colitis or what is the discomfort?
The majority of ulcerative colitis starts slowly, with a few acute onset and occasional acute outbreaks. The course of the disease is chronic, mostly alternating periods of exacerbation and remission, with a few symptoms persisting and gradually worsening. In some patients, intermittent attacks can be triggered by eating disorders, fatigue, mental stimulation, infection and other triggers to trigger attacks or aggravate symptoms.
I. Digestive system manifestations
(A) Diarrhea Paste-like stool or dilute watery stool, pus and blood stool.
(2) Abdominal pain Generally, there is mild to moderate abdominal pain, which is a paroxysmal pain in the left lower abdomen or lower abdomen, and may involve the whole abdomen. There is a pattern of pain – stool – relief after stool. It is often followed by urgency. If complicated by toxic megacolon or inflammation to the peritoneum, there is persistent and severe abdominal pain.
(iii) Other symptoms: Abdominal distension, loss of appetite, nausea, vomiting in severe cases.
(D) Signs In mild and medium-sized patients, there is only light pressure pain in the left lower abdomen, and sometimes the spastic descending colon or sigmoid colon can be palpated. Severe and fulminant patients often have obvious pressure pain and bulging bowel. If there is abdominal muscle tension, rebound pain and diminished bowel sounds, complications such as toxic megacolon and intestinal perforation should be noted.
Second, systemic manifestations are usually seen in medium and heavy patients. Moderate and heavy patients often have low to moderate fever during the active phase, and high fever is often indicative of comorbidities or seen in acute fulminant cases. Severe disease or persistent activity may show weakness, emaciation, anemia, hypoproteinemia, water and electrolyte balance disorders, etc.
Extra-intestinal manifestations The disease may be associated with a variety of extra-intestinal manifestations, including: peripheral arthritis, erythema nodosum, gangrenous pyoderma, outer scleral inflammation, anterior uveitis, recurrent oral ulcers, etc. These extra-intestinal manifestations may resolve or recover after control of colitis or colon resection; sacroiliac arthritis, ankylosing spondylitis, primary sclerosing cholangitis and rare amyloidosis, acute febrile neutrophilic skin disease ( Sweet’s syndrome), which can coexist with ulcerative colitis but are not associated with changes in the condition of ulcerative colitis itself. The incidence of extraintestinal manifestations is reported to be lower in China than abroad.
The clinical typing is based on the course, extent, scope and duration of the disease.
(a) Clinical types: (i) primary type, referring to the first attack without previous history; (ii) chronic relapsing type, which is the most common clinically, with alternating periods of attack and remission; (iii) chronic persistent type, with persistent symptoms, interspersed with acute attacks with worsening symptoms; (iv) acute fulminant type, which is rare and rarely reported in China, with acute onset, severe disease, and obvious systemic toxemia, which may be accompanied by complications such as toxic megacolon, intestinal perforation, and sepsis. The above-mentioned types can be transformed into each other.
(B) Severity of disease Mild: diarrhea less than 4 times a day, light or no blood in stool, no fever, rapid pulse, no or light anemia, normal sedimentation; Medium: between light and heavy; Heavy: diarrhea more than 6 times a day, obvious mucus and blood in stool, body temperature >37.5. C for at least 2 days, pulse >90 times/min, hemoglobin <100g/L, sedimentation >30mm/h.
(iii) Extent of lesion It can be classified as proctitis, rectosigmoiditis, left hemi-colitis (below the splenic flexure of the colon), extensive or total colitis (lesion extending above the splenic flexure of the colon or to the whole colon). The lesions do not extend continuously from the rectum but are regionally distributed and are called regional colitis, which is rare.
(d) Staging of the disease is divided into the active and remission stages.
Common complications of ulcerative colitis.
I. toxic megacolon (toxic megacolon) Most often occurs in fulminant or seriously ill patients, and the incidence is reported abroad to be about 5% in seriously ill patients. At this time, the colon lesions are extensive and serious, involving the muscular layer and the enteromyocardial plexus, the intestinal wall tension is reduced, the colon peristalsis disappears, and the intestinal contents and gas accumulate in large quantities, causing acute colon dilatation, generally the most serious transverse colon. It is often induced by low potassium, barium enema, use of anticholinergic drugs or opiates. Clinical manifestations include rapid deterioration, marked toxemia, with dehydration and electrolyte balance disturbance, bulging bowel, abdominal pressure pain, and loss of bowel sounds. The blood count is significantly elevated and the colon is enlarged and the colonic pouch disappears on X-ray abdominal plain film. The prognosis of this complication is very poor, and it is easy to cause acute intestinal perforation.
The prognosis of this complication is very poor and may cause acute intestinal perforation. Foreign reports have reported the cancer rate of 7.2% and 16.5% after 20 and 30 years of disease respectively.
Other complications The incidence of intestinal hemorrhage in this disease is about 3%. Intestinal perforation is mostly associated with toxic megacolon. Other conditions such as intestinal obstruction and perianorectal lesions are rare, and the incidence is much lower than that of Crohn’s disease.
3.What factors can cause ulcerative colitis?
It is believed that the disease is caused by the interaction of multiple factors, including environmental, genetic, infectious and immune factors. Environmental factors are still unclear.
IBD is not only a polygenic disease, but also a genetically heterogeneous disease (caused by different genes in different people), and patients develop the disease due to genetic susceptibility under the action of certain environmental factors. The role of microorganisms in the pathogenesis of IBD has been emphasized, but so far no constant relationship has been found between a specific microbial pathogen and IBD. New studies suggest that there may be a deficit of immune tolerance to the normal flora in IBD. The intestinal mucosal immune system always plays an important role in the development, progression, and regression of intestinal inflammation in IBD.
4. Why does ulcerative colitis occur?
It is currently believed that environmental factors acting on genetically susceptible individuals, with the involvement of the intestinal flora (or currently unspecified specific microorganisms), initiate the intestinal immune and non-immune systems, ultimately leading to an immune response and inflammatory process, possibly due to persistent stimulation by antigens or (and) disturbances in immune regulation, and this immune inflammatory response manifests itself as overly hyperactive and difficult to self-limit. It is generally believed that UC and CD are different subclasses of the same disease, and the basic pathological process of tissue damage is similar, but may be due to different causative factors and different specific aspects of pathogenesis, ultimately leading to different manifestations of tissue damage.
5.How to diagnose ulcerative colitis?
Those with persistent or recurrent diarrhea and mucopurulent stools, abdominal pain, urgency, with (or without) various degrees of systemic symptoms, and on the basis of exclusion of infectious enteritis such as bacterial dysentery, amebic dysentery, chronic schistosomiasis, intestinal tuberculosis and Crohn’s disease, ischemic enteritis, radiation enteritis, etc., with important changes on colonoscopy (① coarse and finely granular mucosa, diffuse congestion, edema. (2) diffuse erosion or multiple superficial ulcers in obvious lesions; (3) pseudopolyps and bridging mucosa in chronic lesions, and the colonic pouch is often blunt or disappeared) and at least one of the histological findings of mucosal biopsy can diagnose the disease (no conditions for colonoscopy, but X-ray barium enema with X-ray signs (1) coarse mucosal disorder and/or granular (2) multiple superficial ulcers with burr-like or jagged edges and small niche shadows, or inflammatory polyps with multiple small round or ovoid filling defects; (3) disappearance of the colonic pouch, hardening of the intestinal wall, shortening and thinning of the intestinal canal, which may be in the shape of a lead tube), can also diagnose the disease, but is not reliable enough). The disease can also be diagnosed if: the clinical manifestations are atypical but there are typical colonoscopic manifestations and histological findings on mucosal biopsy (or typical X-ray barium enema manifestations); if there are typical clinical manifestations or typical past history but there are no typical changes on colonoscopy or X-ray barium enema, the disease should be classified as “suspected” for follow-up. It should be emphasized that there are no specific changes in this disease, and various etiologies can cause similar inflammatory changes in the intestine, so the diagnosis of this disease can only be made after careful exclusion of all possible relevant etiologies.
6, ulcerative colitis and which diseases are easily confused or which diseases need to be differentiated?
Ulcerative colitis also needs to be distinguished from other diseases, such as
Chronic bacteriophageal dysentery often has a history of acute bacillary dysentery, fecal examination can isolate Bacillus dysenteriae, the positive rate of culture of mucopurulent secretions taken during colonoscopy is high, and antibacterial drug therapy is effective.
The lesion mainly invades the right colon, but may also involve the left colon, the colon ulcer is deeper, the edge is submerged, and the mucosa between the ulcers is mostly normal. The lysosomal amoebic trophozoites or cysts can be found on stool examination, and the amoebic trophozoites can be more easily found by microscopic examination of the ulcerated exudate through colonoscopy. Anti-amoebic treatment is effective.
Schistosomiasis has a history of exposure to epidemic water, often with hepatosplenomegaly, fecal examination can find schistosome eggs, positive hatching trichurias, rectoscopy in the acute stage can be seen in the mucosa yellow-brown particles, biopsy mucosal pressure or histopathological examination found schistosome eggs.
The lesions on colonoscopy and X-ray are mainly in the terminal ileum and adjacent colon and are discontinuous and non-diffuse in distribution and have their characteristic changes, which are generally not difficult to distinguish from ulcerative colitis. However, it should be noted that Crohn’s disease can sometimes manifest as lesions involving the colon alone, and the differential diagnosis is very important at this time, and the key points of differentiation are listed in the following table.
Differentiation of ulcerative colitis and Crohn’s disease of the colon
Item
Crohn’s disease of the colon
Ulcerative colitis
Symptoms
Diarrhea but pus and blood is rare
Pus and blood stools are common
Distribution of lesions
Segmental in nature
Continuous lesions
Rectal involvement
Rare
Mostly involved
Involvement of the terminal ileum
Most common
Rare
Stenosis of the intestinal lumen
Most common, eccentric
Rare, central
Fistula formation
rare
Rare
Endoscopic findings
longitudinal or runner ulcers with normal or cobblestone-like changes in the surrounding mucosa
shallow ulcers, diffuse mucosal congestion and edema, granularity, increased friability
Biopsy features
fissured ulcers, epithelioid granulomas, etc., submucosal lymphocytic aggregates, local inflammation
diffuse inflammation of the entire intrinsic membrane, crypt abscess, marked abnormalities in the structure of the crypt, reduced cupped cells