Elderly Colonic Diverticula

　　Although the etiology of the colonic diverticular wall is not clear, it is generally believed that intestinal lumenal hypertension caused by colonic motor dysfunction and structural defects on the intestinal wall are related to the occurrence of diverticula. According to the characteristic of the colon to propel intestinal contents to the distal end by segmental contraction, a considerable intraluminal pressure can be generated during contraction, and the occurrence of hypertension is related to the excessive or uncoordinated peristalsis of the intestinal tract adjacent to the distal end of the diverticulum. Temporary intestinal obstruction, constipation, intestinal spasm, and drugs (such as when taking opium, the intraluminal pressure can reach 12kPa) can all increase intraluminal pressure, and the mucosa can herniate through the weak spots in the intestinal wall. The intestinal wall between the colon and the colon band is kept taut by the circular muscle, so the place where the blood vessels enter the intestinal wall forms a defect in the circular muscle, which becomes the so-called weak link. Therefore, the site of diverticular prolapse is often between the mesenteric margin of the colon and the opposite margin of the colon band on the mesenteric side, which is also the reason why diverticula are common in elderly, obese, and chronic constipation and colonic disease patients who eat refined wheat flour and other low-fiber foods.

　　The composition of the wall of the colonic diverticula includes herniated colonic mucosa and the serous membrane covering it, but does not contain the muscular layer, so it is actually a pseudodiverticulum. The diameter is not uniform, ranging from a few millimeters to several centimeters. The diverticulum and intestinal lumen are often connected by a narrow pore. Intestinal contents and gas can also enter the diverticulum and are not easy to be expelled, so it often causes secondary diverticulitis due to poor drainage, as well as peridiverticulitis, perforation, peritonitis, abdominal abscess, intestinal fistula, and hemorrhage, and other serious complications. Inflammation can present as acute or chronic according to the duration of the disease course, and with the development of inflammation, intestinal stenosis can occur due to pathological changes such as edema, thickening, and fibrosis of the intestinal wall and surrounding tissues, leading to varying degrees of intestinal obstruction.

　　The main complications of diverticulitis of the colon mainly include the following 4 types:

　　1. Perforation

　　Patients may present with localized peritonitis on the left side, diffuse peritonitis, or an abdominal abscess.

　　2. Hemorrhage

　　It is usually caused by an inflammatory reaction of the basal vascular plexus of the diverticula, resulting in small amounts of bleeding. Elderly patients with atherosclerosis, even if the diverticulitis is not severe, may also cause massive bleeding. 10% to 30% of patients with diverticular disease have intestinal bleeding, which is the most common cause of 3% to 5% of fatal lower gastrointestinal bleeding in the elderly.

　　3. Fistula

　　It is the result of diverticulitis affecting surrounding internal organs or chronic perforation. Abscess rupture can form internal fistulas between the small intestine, uterus, vagina, and bladder, or external fistulas with the abdominal wall. When the colon communicates with the bladder and ureter, it often causes characteristic symptoms such as difficulty in urination, gas in urine, and urinary tract infections. Colonoscopy can differentiate between ulcers, granulomas, colitis, and cancer.

　　4. Intestinal Obstruction

　　It is usually the result of fibrous stenosis caused by the narrowing of the intestinal lumen in subacute or chronic diverticulitis. Patients often have recurrent left lower abdominal pain and progressive constipation. In addition, acute colonic obstruction may occur due to the obstruction of the intestinal lumen by acute inflammation and abscess formation, or acute small bowel obstruction may manifest due to adhesion between the inflamed colon and a segment of small intestine.

　　About 90% of diverticula patients often have no clinical symptoms if diverticulitis is not present, and they are occasionally found during imaging examinations for other digestive system diseases, or they may have very mild symptoms that are not characteristic and often do not attract the attention of patients. Sometimes, they may only be treated as gastrointestinal inflammation without considering the diagnosis of this disease.
　　Typical symptoms of diverticulitis include abdominal pain, fever, nausea, vomiting, bloating, constipation, and diarrhea. Since the sigmoid colon is the most common site of diverticula, abdominal pain is often located in the lower abdomen, especially the lower left abdomen, or along the midline of the lower abdomen, or may manifest as pain in the lower right abdomen depending on the location of the diverticula, with varying degrees of pain. During physical examination, muscle tension and tenderness may be found locally, and inflammatory masses may sometimes be palpated, similar to appendicitis, and therefore, it is sometimes referred to as 'left-sided appendicitis'. Sometimes, patients may present with lower right abdominal pain, and it is more important to distinguish it from appendicitis. Colonoscopy can show changes such as mucosal congestion and edema, and abdominal plain film can show a segment of intestinal loops with congestion, known as the sentinel loop. Barium enema examination may show segmental spasm, mucosal edema, and fixation until the intestinal lumen narrows. However, some believe that colonoscopy is not suitable during the acute inflammatory phase to avoid exacerbating the condition and causing intestinal rupture. Sometimes, the spasm of the longer sigmoid colon segment is difficult to differentiate from obstructive colon cancer, and at this time, it is often recommended to perform fiberoptic colonoscopy. Typical diverticulitis is diagnosed based on symptoms and signs, while elderly, hormone-dependent, and immunodeficient patients may have a delayed response and atypical symptoms.

　　The prevention of elderly colonic diverticula is mainly divided into three aspects.

　　1. Prevention Measures

　　1. Primary Prevention

　　This refers to etiological prevention, where factors that may increase intraluminal pressure should be handled promptly, such as temporary intestinal obstruction, constipation, spasm, and medication. Obstruction should be relieved, stool should be made smooth, intestinal spasm should be relieved, and opium and other drugs should be avoided.

　　2. Secondary Prevention

　　Early identification of diverticular symptoms and early diagnosis are considered as secondary prevention. Typical diverticulitis is diagnosed based on symptoms and signs, while elderly, hormone-dependent, and immunodeficient patients may have a delayed response and atypical symptoms. Colonoscopy, abdominal plain film, or barium enema examination can be performed.

　　3. Third-level Prevention

　　Diverticulosis often occurs in the elderly, and its rehabilitation and prevention of complications are considered as a third-level prevention.

　　2. Risk Factors and Intervention Measures

　　1. Risk Factors

　　Temporary intestinal obstruction, constipation, intestinal spasm, and medication can all increase intraluminal pressure, and the mucosa can herniate through weak spots in the intestinal wall.

　　2. Intervention measures

　　Choose high-fiber diet, such as bran treatment, and avoid factors that may increase intraluminal pressure.

　　Third, social intervention

　　Educate patients on health education, change dietary habits and bad living habits.

　　For elderly, obese, those with constipation, colitis, or chronic intestinal dysfunction caused by frequent drug use, diverticulosis can be considered based on clinical manifestations, but confirmation still requires the results of the following examinations.
　　First, laboratory examination In cases of diverticulovesical fistula, a large number of red and white blood cells may appear in the urine. White blood cell count in the blood increases.
　　Second, other auxiliary examinations
　　1. Sigmoidoscopy: In addition to directly observing the mucosal appearance of the intestinal lumen, it can also take living tissue for pathological examination. It can judge whether there is inflammation or hemorrhage in diverticula, exclude other colonic diseases, but if the intestinal preparation is not satisfactory, or the operator has insufficient experience, it is easy to cause missed diagnosis. And if there is too much insufflation or the colonoscope does not enter the diverticular cavity, there is a possibility of perforation.
　　2. Fiberoptic colonoscopy: The indications for use are the same as those for sigmoidoscopy, but due to its small injury, large observation range, it has a tendency to replace sigmoidoscopy.
　　3. Angiography: Used for the diagnosis of diverticulitis hemorrhage patients.
　　4. Ultrasound: It can be used to observe the formation of perforation or abscess mass in diverticulitis, which is helpful for accurate localization and diagnosis. Diagnosis is based on symptoms and signs, but elderly, hormone-dependent, and immunodeficient patients may have a delayed response and atypical symptoms.

　　Elderly patients with colon diverticula need to pay special attention to their diet, eat less greasy and indigestible foods, and eat light and nutritious food as the main diet. Eat more vegetables and fruits, soft and easily digestible food, and reasonably match the diet. Pay attention to adequate nutrition, avoid smoking and drinking, and avoid spicy food.

　　The treatment plan for colon diverticulosis mainly depends on the patient's symptoms.
　　First, treatment for diverticular inflammatory pain
　　It is inferred that the pain is mainly derived from the spasm or excessive segmental contraction of the colon rather than the inflammation itself. In the past, such patients were often given a low-residue diet, but now it tends to give patients a bowel-moving diet for 3 weeks until symptoms subside. In cases of ineffective treatment, antispasmodic drugs can be added, and some advocate for the trial of sigmoid colonic circular muscle incision, which is reported to be ineffective in 90%. Some also advocate for the trial of sigmoid colonic resection in severe cases.
　　Second, diverticulitis without complications
　　Advocate for conservative treatment. This includes: choosing a high-fiber diet, anti-inflammatory and analgesic (without morphine) for 4 to 5 days. Half of the patients treated with bran can expect symptom relief, 1/3 may still have mild symptoms, and 5% to 10% may have recurrence. Severe cases require hospitalization, and the intestines should be allowed to rest, anti-infection, and prevent and reduce complications. Fasting is required, and those with bloating and vomiting should have a nasogastric tube placed, and those with small bowel obstruction should have a gastric tube inserted. Intravenous fluid replacement is needed to maintain fluid volume, urine output, electrolytes, acid-base balance, and energy intake. Antibiotics should target Gram-negative Escherichia coli and anaerobic Bacteroides fragilis, such as aminoglycosides, cefotetan, and others. Ceftriaxone and beta-lactamase inhibitors can also be used, and antibiotics should be maintained for 7 to 10 days.
　　3. Diverticulitis with Complications
　　1. Surgical Treatment: Emergency surgery is required in the following situations. Diffuse peritonitis caused by perforation of diverticulitis abscess, diverticulitis symptoms still progressing and forming abscesses under antibiotic treatment, intestinal obstruction, sepsis, secondary colovesical fistula, antibiotic treatment is ineffective. Emergency surgery is dangerous, especially for the elderly with deteriorated cardiorespiratory function. There are various surgical methods for treating diverticulitis. The first method is to perform elective surgery for diverticulosis, the second method is to first excise the involved intestinal segment, and then close the colonic fistula. The third method is to first perform a transverse colostomy and pelvic drainage, and then excise the involved intestinal segment, finally close the colonic fistula, and this method is now rarely used. Specifically: ①Peritonitis: If it is localized, non-surgical treatment under strict observation is the main. If the inflammation is diffuse or a abscess has formed, active surgical treatment should be given. During surgery, the diseased segment of the intestinal tract is only inflamed and is not routinely performed right hemicolectomy, but abdominal lavage and pus drainage. If there is intestinal perforation, it was common to perform a transverse colostomy in the past, but due to its incidence rate of up to 10% to 30%, a large amount of feces in the left colon may still leak out through the perforation. Currently, some people advocate performing primary colectomy and anastomosis after exploration if the perforation lesion is clearly found (except for the elderly and weak). ②Fistula: Patients may form a fistula due to adhesion between the sigmoid colon and the bladder vaginal fornix or small intestinal loop. Spontaneous fecal fistula patients may present with chronic illness, lower abdominal tenderness, intermittent diarrhea, urinary gas, and vaginal defecation, etc. This fistula often cannot heal itself, and even if colostomy is performed simultaneously, most patients should undergo sigmoid colectomy and primary anastomosis, and at the same time repair the involved organs and fistula orifices. ③Blood loss: If massive bleeding is not controlled by non-surgical treatment, it can be first located by angiography, and if the patient's condition permits, a primary resection and anastomosis of the bleeding intestinal segment or a staged operation of intestinal resection and colostomy can be performed. ④Abdominal abscess: If non-surgical treatment is ineffective, surgical drainage and proximal colostomy can be performed.
　　2. Optimal Treatment Plan: Diet therapy, anti-inflammatory and analgesic.
　　3. Rehabilitation Treatment: Regular follow-up, further treatment if complications occur, and health education for patients.