OVERVIEW
Diverticulosis of the colon is a pouch-like structure that protrudes outward from the mucosal and submucosal layers of the colon through the muscularis propria, and is characterized morphologically by being located between the mesentery of the colon and the opposite mesentery of the two colons, and protruding sacs from the wall of the colon, or arranged in bunches along the side of the colonic band. The sigmoid colon, the descending colon is most often involved, diverticula are divided into 2 categories, true (congenital) diverticula and pseudo (acquired) diverticula. Congenital diverticula including the whole colon are rare, and most of the diverticula without muscular layer are pseudodiverticula, and they are caused by acquired factors.
Etiology
The rapid prevalence of acquired diverticular disease in Western countries in the middle of the 20th century can be attributed to a decrease in dietary fiber consumption. The increased prevalence of diverticulosis and its complications in industrially developed countries is attributed to the replacement of coarse food items with flour and refined sugar in the diet.
Symptoms
1. Diverticulosis of the colon
Approximately 80% of patients with diverticular disease of the colon are asymptomatic and are discovered accidentally during a barium x-ray or endoscopy. Symptoms associated with the diverticulum are actually symptoms of its complications such as acute diverticulitis and bleeding; symptoms such as episodic abdominal pain, constipation, diarrhea, etc. in uncomplicated patients are due to concomitant gastrointestinal dynamics disorders and the presence of diverticulum is only coincidental. On physical examination, there may be mild tenderness in the left lower abdomen, and sometimes a hard tubular structure may be visualized in the left colon.
2. Acute diverticulitis
Acute diverticulitis is the most common complication of colonic diverticulosis, with acute onset of limited abdominal pain of varying degrees, which may be stabbing, dull and colicky, mostly in the left lower abdomen, occasionally located in the suprapubic area, right lower abdomen, or the entire lower abdomen. Patients often have constipation or frequent bowel movements, or both, and the pain can be relieved after passing gas. Inflammation adjacent to the bladder may produce frequent and urgent urination. Depending on the location and severity of the inflammation, nausea and vomiting may also occur.
3. Acute diverticulitis complicated by abscesses
The most common complication of acute diverticulitis is the development of an abscess or loose connective tissue infection, which can be located in the abdomen, pelvis, retroperitoneum or scrotum. Often in the abdomen or pelvic rectal examination can be found in a tender mass, causing abscesses are also accompanied by different degrees of signs of sepsis.
4. Acute diverticulitis complicating diffuse peritonitis
When a confined abscess ruptures or the diverticulum perforates freely into the abdominal cavity, it can cause purulent or fecal diffuse peritonitis. Most of these patients present with acute abdomen and varying degrees of severe infectious toxic shock.
5. Acute diverticulitis with fistula formation
Fistulas occur in approximately 2% of all patients with acute diverticulitis. Internal fistulas may arise from adhesions of adjacent organs to the diseased inflamed colon and adjacent mesentery, with or without the presence of an abscess. As the inflammatory process worsens, the abscess of the diverticulum decompresses on its own and ulcerates into the adherent cavitary organ, resulting in the formation of a fistula.
6. Acute diverticulitis complicating intestinal obstruction
Complete colonic obstruction due to domestic diverticulosis is uncommon, but partial obstruction due to edema, spasm, and inflammatory changes of diverticulitis is common.
Examination
Endoscopy, gas-barium double-contrast enema angiography, and CT scanning of the abdomen and pelvis are helpful in the diagnosis. Endoscopy should generally be avoided in acute situations, as insufflation can induce perforation or aggravate a pre-existing perforation. Barium enema can be used to diagnose acute diverticulitis, but there is a risk of barium spillage into the abdominal cavity, which can cause severe shock and death. If a more urgent diagnosis is needed to guide treatment, a water-soluble contrast enema can be used so that even if there is spillage of contrast into the abdominal cavity, it will not cause a serious reaction.
CT scanning is non-invasive and can usually confirm clinical suspicion of diverticulitis. Enhanced visualization of the rectum during scanning can make the detection of diverticular abscesses or fistulas more sensitive than radiography alone, and CT scanning can also guide percutaneous puncture to drain abscesses.
Abdominal radiographs may show colonic obstruction secondary to sigmoid colon lesions. Water-soluble contrast enema contrast may confirm the diagnosis.
Diagnosis
The diagnosis can be confirmed on the basis of clinical manifestations and laboratory tests.
Treatment
1. Internal medicine treatment
Acute diverticulitis without complications can be treated with internal medicine, including fasting, gastrointestinal decompression, intravenous fluid replacement, broad-spectrum antibiotics and close clinical observation. Generally, gastrointestinal decompression is used only when there is vomiting or evidence of colonic obstruction.
2. Surgery
Surgery should be performed in the following cases: (1) the first attack of acute diverticulitis is unresponsive to medical treatment; (2) acute recurrent diverticulitis should be considered for selective resection when recurrence occurs, even if the first attack has been satisfactorily treated by medical treatment; (3) patients <50 years of age who have had an attack of acute diverticulitis and have been successfully treated by medical treatment should be subjected to elective surgery to avoid emergency surgery in the future; (4) patients who have diverticulitis due to immune deficiencies should be subjected to surgery only when they have been treated with intravenous fluids and antibiotics. Diverticulitis in immunodeficient patients cannot provoke enough inflammatory reaction, so it is a fatal disease, and perforation and rupture into the free abdominal cavity are very common, therefore, for patients who have had an attack of acute diverticulitis in the past, selective resection should be performed to eliminate the risk of diverticulitis recurrence which may lead to various complications before long-term immunosuppressive treatment is needed; (5) Acute diverticulitis is accompanied by abscesses or loose connective tissue (5) acute diverticulitis with abscess or loose connective tissue inflammation; (6) acute diverticulitis with diffuse peritonitis; (7) acute diverticulitis with fistula formation; (8) acute diverticulitis with colonic obstruction.