Bowel radiation damage: symptoms

Symptoms of radiation enteritis can occur quite early, during the period of radiotherapy; sometimes shortly after treatment, but their development is possible even after several months and even years after its completion. Early nausea, vomiting, upset of the stool in the form of diarrhea or constipation may occur. Involvement in the pathological process of the colon is caused by tenesmus, the appearance of mucus and scarlet blood in feces as a result of the formation of ulcers in the mucosa of the lower intestinal segment (10% of cases), predominance of diarrhea at first, then constipation due to the early appearance of strictures of the colon or rectum. The prevalence in the clinical picture of signs of involvement of the small intestine at an early stage is characterized by cramping pains in the abdomen, nausea, increased peristalsis, watery stools, swelling, rumbling, and pouring. Sometimes these symptoms disappear rather quickly, but in a number of cases they remain for a long time or are renewed a few months after irradiation. Radiation diarrhea develops mainly due to a decrease in the reabsorption of bile acids by the damaged mucous membrane of the ileum, which inhibits the reabsorption of water by the large intestine. Reactive inflammation of the mucous membrane of the small intestine is accompanied by a disorder of the membrane digestion, dysbiosis. The depletion and disruption of the maturation of absorbent villus cells leads to a decrease in the activity of the enzymes of the "brush" fringe. A breath test can detect a violation of absorption of lactose, D-xylose, glycocholates, vitamin B12. Perhaps a moderate disorder of fat absorption, more often in an acute period. However, the asymptomatic course of the disease is described even with significant damage to the intestinal mucosa.

The absence of acute, early signs of intestinal lesions does not guarantee the appearance of late, radiation-induced changes in the intestine. The latent period, i.e. The interval between the time of irradiation and the appearance of signs of intestinal lesions varies in very large ranges - from 3 months to 31 years. The frequency of late intestinal manifestations of radiation therapy is approximately 10%. In this period, the most characteristic symptom of radiation enteritis is colicky abdominal pain, caused by a partial small intestinal obstruction, which sometimes turns into total obstruction. There may be nausea, vomiting, signs of impaired absorption of varying degrees. Intestinal obstruction is usually caused by local mechanical constriction of the intestine, but can be caused by the presence of non-functioning areas that prevent normal peristalsis. There may be simultaneous involvement of many segments of the gut. Clinical examination of the patient shows signs of intestinal obstruction and palpable-defined dense formations in the abdominal cavity, the appearance of which is associated with inflammation of the intestine and mesentery. Between the pelvic organs and the organs of the abdominal cavity formation of fistulas is possible. In such cases, there are symptoms such as turbid vaginal discharge, pneumaturia and the rapid appearance of undigested food in the liquid stool. Evidence of the formation of rectovaginal fistula is the appearance of signs of proctitis. Abscesses are usually localized in the small pelvis and can lead to peritonitis and sepsis. Perforation of the ileum and large intestine, although relatively rare, can also cause acute peritonitis. Occasionally, massive intestinal hemorrhage due to ulceration of the ileum and large intestine is noted.

With extensive defeat of the small intestine, the symptoms of the syndrome of impaired absorption appear to the fore in the clinical picture. In such patients, along with a significant, recently emerged, unexplained weight loss of the violation of intestinal absorption testify such tests as the determination of fat in feces, the absorption of vitamin B12, the respiratory test for bile acids, the absorption of D-xylose. The violation of absorption of bile acids promotes both diarrhea and steatorrhea.

[1], [2], [3], [4], [5], [6], [7]