Radiation proctitis

　　Radiation proctitis is also a common complication of pelvic radiotherapy. Women with cervical cancer, vulvar and vaginal cancer, and anal and rectal cancer are treated with radioactive radium, cobalt, cesium, and other radioactive elements for radiation therapy. These radioactive elements have inhibitory effects on cancer and also damage normal tissue. When they damage the rectal mucosa, they can cause radiation proctitis. Therefore, radiation proctitis caused by radiotherapy is more common in clinical practice.

　　Proctitis may only involve the mucosa in mild cases, while in severe cases, the inflammation may affect the submucosal layer, muscular layer, and even the surrounding tissue of the rectum. Sometimes only a part of the rectal mucosa is involved, and sometimes the entire rectal mucosa may be inflamed, and the mucosa of the colon may also be inflamed. The first priority is to examine the proctitis, as only detailed diagnosis of the condition of the enteritis can allow for symptomatic treatment.

　　If proctitis is not treated in time, it may develop into colorectal cancer. The early stage may not be noticeable, but the immune system will significantly decline, and there may be problems with gynecology or male prostate, which will occur later. At this time, it is generally accompanied by colitis, as 50% of the human immune system is in the colon, so many sexual problems may arise.

　　The main complications caused by radiation colitis include intestinal stricture and obstruction, rectovaginal fistula, rectovesical fistula, or ileocecal fistula, gastrointestinal ulcers and perforations, and induction of colorectal cancer, etc.

　　Rectal bleeding, which is bright red or dark red, usually occurs during defecation and is generally a small amount of bleeding, occasionally in large amounts. After erosion, necrotic tissue may fall off and be expelled, with an odor, anal and rectal soreness or burning pain, and later, tenesmus may appear due to stimulation of the anal sphincter.

　　1. Early symptoms: Due to the reaction of the nervous system to radiation, gastrointestinal symptoms may appear early. Generally, they appear within 1 to 2 weeks after the start of radiotherapy. Nausea, vomiting, diarrhea, and the expulsion of mucus or bloody stools. Involvement of the rectum is accompanied by tenesmus. Persistent hematochezia can lead to iron deficiency anemia. Constipation is rare. Occasionally, there may be low fever. Abdominal pain-type irritable bowel syndrome suggests involvement of the small intestine, and sigmoidoscopy may show mucosal edema and congestion, and in severe cases, erosion or ulcers may be present.

　　2. Late symptoms: If the symptoms during the acute stage do not subside or if there are significant symptoms 6 months to several years after radiotherapy ends, it indicates that the lesion continues and will eventually develop into fibrosis or stricture. The symptoms during this period may occur as early as half a year after radiotherapy, or as late as 10 or even 30 years later, and are often related to intestinal wall angiitis and persistent lesions.

　　The late manifestations of radiation colitis and the recurrence and metastasis of tumors require X-ray barium enema, mesenteric angiography, endoscopic examination, and biopsy for differentiation. In differential diagnosis, other diseases should be considered, such as non-specific ulcerative colitis, Crohn's disease, intestinal tuberculosis, and intestinal lipometabolic disorder syndrome.

　　1. Prevention

　　During radium therapy for cervical cancer, the radium applicator should be fixed sufficiently to prevent displacement and avoid tilting towards the posterior vaginal wall. During external irradiation, the distance between the two pelvic irradiation fields should be not less than 4-6 cm. It is better to reduce the number of radium therapy sessions from 3-4 to 2. Some use a post-loading treatment machine, designed with a special straight push spreader, which can separate the anterior rectal wall and vaginal container by 1.5 cm to reduce the radiation dose to the rectum. Those with radioactive proctitis should suspend radiotherapy and undergo other treatments.

　　2. Prognosis

　　The prognosis of radiation enteritis is worse than that of radiation colitis and proctitis. Two-thirds of mild patients can improve or recover within 4-18 months. Some believe that extensive pelvic surgery, followed by further radiotherapy, may result in poor blood supply to the lesion tissue, and the prognosis is often poor. According to foreign reports, the mortality rate of severe intestinal radiation injury is 22%.

　　1. Rectal examination: In cases of early radiation proctitis or mild injury, digital examination may show no special findings. There may only be anal sphincter spasm and tenderness. Some anterior rectal walls may have edema, thickening, hardening, and bloodstaining on the gloves. Sometimes, ulcers, narrowing, or fistulas can be felt, and in 3% of severe rectal damage cases, rectovaginal fistula may form. A vaginal examination can help with diagnosis at the same time.

　　2. Endoscopic examination: In the first few weeks, intestinal mucosal congestion, edema, granular changes, and increased fragility can be seen, and it is easy to bleed when touched, especially on the anterior rectal wall. Subsequently, there is thickening, hardening, and characteristic capillary dilation, ulcers, and narrowing of the intestinal lumen. Ulcers can be patchy or perforating, with varying sizes and often located on the anterior rectal wall at the level of the cervix. The narrowing of the rectum is often located 8-12 cm above the anal margin. Some colonic lesions are similar to ulcerative colitis. The thickened and hardened mucosa and the ring-shaped narrowed intestinal segments or the hard perforating ulcers, if the peripheral capillary dilation is not obvious, can be mistaken for a tumor. Tissue biopsy can help with diagnosis, but one should be cautious to prevent perforation.

　　3. X-ray examination: Barium enema examination of the intestines helps to determine the extent and nature of the damage. However, the signs are not specific. Barium enema shows the colon mucosa with fine serrated edges, irregular folds, and rigid or spasmodic intestinal wall. Sometimes, narrowing, ulcers, and fistula formation can be seen in the intestinal segments. In a few cases, the mucosa at the edge of the ulcer can bulge, and the X-ray signs are similar to a tumor. The differential point is that there is a gradual transition between the lesion segment and the normal intestinal segment without an abrupt boundary, unlike a tumor. The sigmoid colon is located lower and folded into an angle. It is of great importance to take different angle photographs for the differential diagnosis of the nature of the lesions.

　　Barium examination of the small intestine shows that the lesions are often located at the terminal ileum. During barium administration, irregular narrowing of the lumen can be seen, and the adhesions can pull the angle and form thorn-like shadows. The intestinal wall thickens, and the distance between intestinal loops widens. There may also be nodular filling defects in the intestinal lumen, similar to inflammatory bowel disease. The normal feather-like mucosal patterns of the small intestine disappear during emptying. In recent years, mesenteric angiography has helped to discover small vessel lesions. It has certain significance for the early diagnosis and differential diagnosis of radiation enteritis.

　　Measurement of small intestinal absorption function: including stool fat determination, vitamin B12 and D-trehalose absorption test.

　　1. It is recommended to eat more high-energy and high-protein foods to compensate for the nutritional consumption caused by long-term diarrhea. The supply amount can be gradually increased according to the patient's tolerance for digestion and absorption. Generally, the energy supply is 40 kcal per kilogram of body weight per day. The protein supply is 1.5 grams per kilogram of body weight per day, with 50% being high-quality protein.

　　2. Ensure an adequate intake of vitamins and inorganic salts to compensate for the nutritional loss caused by diarrhea.

　　3. Limiting fat and dietary fiber is also an important aspect of dietary considerations for radiation proctitis: diarrhea is often accompanied by poor fat absorption, and severe cases may have steatorrhea. Therefore, the amount of dietary fat should be limited, and low-fat foods and cooking methods should be used. For those with steatorrhea, medium-chain triglyceride oils can be used. Avoid eating foods that are high in刺激性 and fiber, such as spicy foods, sweet potatoes, radishes, celery, raw vegetables, fruits, and刺激性 herbs like scallions, ginger, and garlic, as well as coarse grains and dried beans.

　　4. Eat less and more meals: To reduce the burden on the intestines, supplement the intake of nutritional intake in a way of eating less and more meals.

　　一、Regulation

　　The patient should rest in bed, eat thin, soft, low-fiber, and nutritious food, maintain smooth defecation, take a hot sitz bath after defecation, apply heat compresses to the anal area to reduce local irritation.

　　二、General treatment

　　1. To reduce intestinal infection and inflammation, sulfonamides, tetracycline, berberine, or andrographolide can be given to control intestinal inflammation. For abdominal pain and diarrhea, compound benzylpiperidine, prucalpine, atropine, and other drugs can be given to relieve spasm and reduce diarrhea. The efficacy of Western medicine in the treatment of this disease is not ideal, with significant side effects and a high recurrence rate.

　　2. Traditional Chinese Medicine and Chinese herbs: The efficacy of Chinese medicine in the treatment of this disease is encouraging. Traditional Chinese medicine believes that this condition is caused by injury to the body's vital energy, leading to ulceration of the intestinal mucosa. The treatment should focus on strengthening the body and nourishing Qi and blood, with the addition of clearing heat and removing dampness to promote ulcer healing and inflammation subsidence. The clinical typing of radiation proctitis is conducive to treatment and prognosis judgment. According to the clinical manifestations and course of the disease, it is divided into the following four types:

　　① Mild type: most common, slow onset, mild symptoms, mild diarrhea, less than 4 times a day, alternating with constipation, without or with only a small amount of blood and mucus in the stool, without systemic symptoms, the lesion is mostly limited to the rectum and sigmoid colon, and blood condition is normal.

　　② Moderate type: between mild and severe, diarrhea more than 4 times a day, with mild systemic symptoms.

　　③ Severe type: with fever, fatigue, emaciation, anemia, and other systemic manifestations, diarrhea more than 6 times a day, with hematochezia or mucous purulent stools.

　　④ Fulminant type: rare.

　　3. Understanding of Traditional Chinese Medicine: It is believed that colitis is mostly caused by damp-heat obstruction, deficiency of spleen and kidney yang, deficiency of both Qi and blood, Qi stagnation and blood stasis, dietary imbalance, overexertion, and mental factors. Through over 20 years of clinical experience and the joint efforts of many experts, a relatively complete and unique TCM typing and treatment method has been summarized, which has achieved remarkable effects in clinical practice, thus having a certain role in curing colitis and preventing colorectal cancer.

　　① Diarrheal type: diarrhea, loose stools, abdominal pain, hematochezia, mucous stools, purulent stools, bowel sounds, and poor defecation, accompanied by emaciation, general fatigue, aversion to cold, dizziness, and other symptoms. (This type is the easiest to treat, and it can usually be cured within 20-60 days.)

　　② Constipation type: constipation, like sheep dung, defecation is not smooth and not complete, and even cannot defecate for several days. Some patients have a history of long-term diarrhea, accompanied by abdominal pain, weight loss, dry mouth, distension, anemia, and are prone to malignancy. (Treatment usually lasts for 30-60 days)

　　③ Diarrhea and constipation alternating type: stools are dry and loose at times, with mucus and blood, accompanied by abdominal pain and distension, etc. (Treatment usually lasts for 20-60 days)

　　Third, local treatment

　　1. Use 50-100 milliliters of peony and licorice decoction mixed with 50-100 milliliters of hawthorn fluid, retain enema twice a day.

　　2. If the rectal mucosa is ulcerated, 1% hydrocortisone acetate solution can be applied to the surface once a day; or use 2% gentian violet solution once a day; or use indomethacin suppositories inserted into the rectum twice a day.

　　3. If there is rectal stenosis but can be inserted with a finger, dilation can be performed every 2 weeks or once a week, lasting for several months. If it cannot be inserted with a finger, or there is already a rectovaginal fistula, surgical treatment should be adopted. However, due to tissue damage from radiation, the wound after surgery is not easy to heal, and it should be carefully considered.

　　Fourth, general treatment

　　During the acute stage, bed rest should be taken, and the diet should be non-irritating, easy to digest, and nutritionally rich, with multiple small meals as a principle. Limit the intake of fiber, and those with severe diarrhea can adopt intravenous hyperalimentation therapy.

　　Fifth, drug treatment

　　1. Astringent antispasmodic: Datura stramonium compound camphor tincture, hawthorn bark decoction, aspirin can effectively control the early diarrhea of radiation enteritis, which may be related to the inhibition of prostaglandin synthesis.

　　2. Local analgesics and stool softeners: Those with significant tenesmus and pain can use benzocaine cottonseed oil, retain enema with warm paraffin oil for retention enema, or take a warm bath with water.

　　3. Hormonal enema: Add succinate hydrocortisone to warm saline, retain enema, especially effective for those with tenesmus.

　　4. Pre-sacral sealing therapy: Procaine, Vitamin B6, vitamins, -chymotrypsin, streptomycin, sealing once every 5-7 days for 1-3 treatments can significantly alleviate pain.

　　5. Hemostasis: Low-position intestinal bleeding can be stopped by pressing under the direct vision of an endoscope or using hemostatic agents or performing an '8' suture at the bleeding point.

　　6. Antimicrobial infection: Antibiotics should be used when secondary infection occurs.