Radiation enteritis is an inflammatory condition that affects the intestines, arising as a side effect of radiation therapy, a common cancer treatment. This inflammation primarily impacts the small and/or large intestines, causing discomfort and disrupting normal digestive function. The condition can manifest in varying degrees of severity, impacting a patient’s quality of life during and after cancer treatment.
What is Radiation Enteritis?
Radiation enteritis is an inflammatory response within the intestinal lining, triggered by exposure to radiation, most frequently as part of cancer treatment. Radiation therapy targets rapidly dividing cancer cells, but it can also affect healthy, fast-growing cells in the intestinal lining, leading to damage and subsequent inflammation. This damage can disrupt the intestine’s normal function.
The condition is categorized into two forms: acute and chronic, based on their onset and duration. Acute radiation enteritis typically develops during the course of radiation treatment or within weeks following its completion, with symptoms often resolving within a few weeks to months. In contrast, chronic radiation enteritis can emerge months or even years after radiation therapy has concluded, sometimes as long as 3 to 30 years post-treatment. While acute forms are common, affecting up to 90% of those receiving pelvic radiation, chronic forms are less frequent, developing in 5–55% of patients.
Identifying the Symptoms
Symptoms of radiation enteritis can vary in their presentation and severity, depending on whether the condition is acute or chronic. Acute symptoms, which appear during or shortly after radiation therapy, often include nausea, vomiting, and diarrhea. Patients may also experience abdominal pain or cramping, a frequent or urgent need to have bowel movements, and a loss of appetite. Rectal pain and the discharge of mucus or blood from the rectum can also occur with acute forms.
When radiation enteritis becomes chronic, symptoms can persist or develop months to years after treatment, sometimes becoming more severe. Persistent diarrhea, often accompanied by abdominal pain, is a common feature. Malabsorption of nutrients can lead to weight loss and fatigue, as the damaged intestine struggles to absorb food properly. More serious complications can include intestinal strictures, which are narrowings of the bowel that can cause blockages, or fistulas, abnormal connections between different parts of the intestine or to other organs. Bleeding from the rectum may also be a symptom of chronic radiation proctitis, a specific form of radiation enteritis affecting the rectum.
Treatment and Management Approaches
Managing radiation enteritis involves a comprehensive approach, often tailored to the specific symptoms and severity of the condition. Dietary modifications are frequently a first step, with recommendations often including a low-fiber, low-fat, and lactose-free diet to reduce irritation to the digestive system. Patients are often advised to avoid certain foods such as raw vegetables, strong spices, greasy foods, and dairy products (excluding yogurt), while incorporating easily digestible options like cooked lean meats, bananas, applesauce, and white bread. Maintaining adequate hydration is also important.
Medical interventions play a significant role in symptom control. Anti-diarrheal medications are commonly prescribed to reduce stool frequency and urgency. Anti-inflammatory medications, such as corticosteroids, may be used to reduce inflammation in the intestines. For patients experiencing pain, appropriate pain relievers can be administered. If bacterial overgrowth is suspected, antibiotics may be prescribed.
For more severe or chronic cases, additional treatments may be necessary. Nutritional support, including supplements for malabsorption or, in some instances, tube feeding, may be required if patients are not receiving enough nutrients. Endoscopic procedures can be performed to address specific issues, such as dilating strictures or managing bleeding. In rare and severe situations where complications like bowel obstruction, perforation, or persistent bleeding occur, surgical intervention may be considered to remove damaged sections of the intestine or bypass them. This multidisciplinary approach typically involves oncologists, gastroenterologists, dietitians, and other specialists.
Strategies for Prevention
Preventive strategies for radiation enteritis focus on minimizing radiation exposure to healthy intestinal tissues during cancer treatment. Modern radiation techniques, such as intensity-modulated radiation therapy (IMRT) and image-guided radiation therapy (IGRT), are designed to deliver radiation more precisely to the tumor while sparing surrounding healthy organs, including the intestines. Custom positioning devices and protective shields for the bowel or rectum are also used to further limit exposure.
Dietary advice before and during treatment can also contribute to prevention. Patients may be advised to avoid foods that could irritate the gut, such as those high in fiber, spicy foods, and certain dairy products. Prophylactic medications or supplements may be considered in some cases to protect the gut lining.