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Radiation-Induced Enteritis

Radiation Enteritis

Radiation enteritis is a condition that arises as a side effect of radiotherapy during the treatment of cancer. It may cause gastrointestinal symptoms such as a change in bowel habits and abdominal pain, which may be acute or chronic.


Radiation enteritis (RE) is an iatrogenic ailment that involves injury to the small intestine, resulting from radiation therapy employed in the treatment of malignancies. RE affects the majority of patients undergoing radiation in the abdomen or pelvis [1]. Factors that predispose patients to RE entail high dose radiotherapy, cardiovascular disease, and those simultaneously receiving chemotherapy.

RE may be acute or chronic in nature. Acute disease may present with abdominal pain, in addition to a variety of nonspecific gastrointestinal (GI) symptoms such as nausea, vomiting, anorexia, and change in bowel habits. These occur and peak with 2 to 5 weeks of initiation of therapy [2]. Acute RE often resolves spontaneously, after 3 months of treatment [3].

Chronic RE has a much slower onset and may transpire years after exposure to radiotherapy [4]. It occurs due to repeated injury of the gut, leading to inflammation and atrophy of mucosal cells, fibrosis, and impaired healing [5]. The nature and severity of symptoms correspond with the associated damage [6]. Furthermore, radiotherapy affects local blood vessels, causing arterial occlusion by surrounding tissues, that is, endarteritis obliterans, leading to chronic ischemia. Chronic RE manifests as nonspecific GI symptoms, bowel obstruction, fat malabsorption and abdominal pain associated with food intake [7]. Micronutrient deficiencies, such as vitamin B12 and calcium, are also known findings.

  • CONCLUSIONS: If untreated the side-effects of CRE have a disabling affect on sufferers, who may be reluctant to seek help about their symptoms. Health professionals need to be more pro-active in identifying and caring for sufferers of CRE.[ncbi.nlm.nih.gov]
  • In some states, plans may be available to persons under age 65 who are eligible for Medicare by reason of disability or End-Stage Renal Disease. Not connected with or endorsed by the U.S. Government or the federal Medicare program.[aarpmedicareplans.com]
  • Discussion Radiation enteritis causes considerable disability, and in many cases can be avoided.[ro-journal.biomedcentral.com]
  • This patient group can undoubtedly gain substantial benefit from a more coherent approach to care for their ongoing and often disabling and distressing symptoms.[doi.org]
  • Patients with LT3S suffered longer duration of hospitalization (48.25   23.29 days in LT3S vs 26.75   10.56 days in euthyroid, P   0.036).[ncbi.nlm.nih.gov]
Pleural Effusion
  • Laparoscopic surgery did not significantly decrease postoperative morbidity but did decrease the pleural effusion rate.[ncbi.nlm.nih.gov]
  • During irradiation, diarrhea occurred in 69% and 66% of the 5-ASA and placebo groups, respectively (chi2, P 0.22). Curves of survival without diarrhea did not differ between groups (logrank P 0.09).[ncbi.nlm.nih.gov]
  • NOS ( R19.7 ) functional diarrhea ( K59.1 ) infectious gastroenteritis and colitis NOS ( A09 ) neonatal diarrhea (noninfective) ( P78.3 ) psychogenic diarrhea ( F45.8 ) due to radiation K52.0 Enteritis (acute) (diarrheal) (hemorrhagic) (noninfective)[icd10data.com]
  • Spicy foods trigger diarrhea for many. (Image: Philhillphotography/iStock/Getty Images) Each individual has different types of foods that trigger diarrhea, and for many the offending source is spicy foods.[livestrong.com]
  • All four patients were treated and observed for over one year, with follow-up observations now extending to over three years.[ncbi.nlm.nih.gov]
Chronic Diarrhea
  • The following suggestions can help you manage chronic diarrhea: If this is a new symptom, tell your doctor about it.[oncologynutrition.org]
  • If broth is used instead of water, omit the salt. 18) Many RD's use glutamine therapy to help those people with chronic diarrhea that does not resolve with other dietary changes. Use 10 gm three times per day mixed with clear juice or water.[cancerrd.com]
Chronic Abdominal Pain
  • To increase the diagnostic yield of radiation enteritis, capsule endoscopy was performed in patients having anemia or chronic abdominal pain after chemoradiotherapy. RESULTS: Fifteen patients were enrolled between June 2007 and December 2008.[ncbi.nlm.nih.gov]


RE is a significant problem, as it negatively impacts the quality of life. Furthermore, the condition may not receive adequate attention and treatment due to patients being less forthcoming about GI complaints, as well as clinicians failing to recognize and refer the former to specialists [1] [8]. It is thus important to educate patients about the possible gastrointestinal side effects of radiotherapy and encourage a preventative health-seeking behavior. In radiation enteritis, the medical history is of significant importance, as it may reveal radiotherapy exposure, possibly many years prior to presentation. Clinical examination further aids in diagnosis.

Biochemically, chronic RE may be evidenced by anemia and malnutrition [9]. Sepsis and raised inflammatory markers may be observed if there is an intestinal obstruction. There may also be a concurrent electrolyte imbalance, abnormal liver function tests, and coagulopathy.

Radiological techniques are useful, as there are a number of changes that are detectable. Computed tomography (CT) and magnetic resonance imaging (MRI) scans may show signs of intestinal wall inflammation such as thickening of the bowel walls, edema, and features of intestinal obstruction. Fistula formation, between the bowel and adjacent pelvic structures, may also be visualized in this way. The small bowel, as inspected via fluoroscopic enteroclysis, may exhibit signs of edema and fibrosis, stenosis and ulcers. There may be segments that appear similar to a stack of coins. Other radiological exams carried out include barium studies. Invasive techniques include endoscopy.

Several gastrointestinal disorders may be considered as differential diagnoses, such as Crohn's disease, malignant metastases, ischemia and enteritis due to alternative agents.

Pleural Effusion
  • Laparoscopic surgery did not significantly decrease postoperative morbidity but did decrease the pleural effusion rate.[ncbi.nlm.nih.gov]


  • Abstract Acute radiation enteritis is almost inevitable in the curative treatment of malignant tumors of the abdomen and pelvic area.[ncbi.nlm.nih.gov]
  • Acute RE often resolves spontaneously, after 3 months of treatment. Chronic RE has a much slower onset and may transpire years after exposure to radiotherapy.[symptoma.com]


  • Cox survival analysis taking into account the stage of the cancer and the age at diagnosis showed that rectal bleeding is a factor with a prognosis significantly poorer than the mild symptoms (p 0.05), equivalent to that of the severe complications.[ncbi.nlm.nih.gov]
  • What is the Prognosis of Radiation Enteritis? (Outcomes/Resolutions) The prognosis for Radiation Enteritis is very good when the symptoms are acute.[dovemed.com]
  • Outlook (Prognosis) When the abdomen receives radiation, there is always some nausea, vomiting, and diarrhea. In most cases, the symptoms get better within 2 - 3 months after treatment ends.[nicklauschildrens.org]


  • We reviewed the etiology, prevalence, symptoms, diagnosis and management of CRE and CRE with malnutrition in this article. Functional short bowel syndrome as a cause of malnutrition in CRE is also considered.[ncbi.nlm.nih.gov]
  • Etiology and Pathophysiology Radiation injury activates intracellular mechanisms which alter cell division, leading to inflammation or cell death. Injury likely mediated indirectly by free-radical release, affecting DNA repair.[unboundmedicine.com]
  • (Etiology) Radiation therapy is commonly used to treat cancer and it employs the use of high-energy particles or waves, such as x-rays, gamma rays, electron or proton beams, to destroy cancer cells by damaging their DNA Intestinal lining cells, which[dovemed.com]


  • CMCR and oncology clinical trial group leaders were joined by experts in epidemiology and quality of life issues, representatives from the pharmaceutical industry, patient advocates, and U.S. Food and Drug Administration (FDA) officials.[doi.org]
Sex distribution
Age distribution


  • A hypodeiodination condition and a potential pituitary-thyrotroph dysfunction might play a role in the pathophysiology of LT3S in RE. Worse nutritional status and clinical outcomes were confirmed in RE patients with LT3S.[ncbi.nlm.nih.gov]
  • Etiology and Pathophysiology Radiation injury activates intracellular mechanisms which alter cell division, leading to inflammation or cell death. Injury likely mediated indirectly by free-radical release, affecting DNA repair.[unboundmedicine.com]
  • Pathophysiology Ionising radiation generates free radicals from intracellular water, which in turn affect DNA synthesis. Cells with a high proliferation rate tend to be more susceptible to radiation injury.[surgwiki.com]
  • Pathophysiology of side effects of cancer therapies Chemotherapy Cytotoxic chemotherapy agents have a direct effect on the GI mucosa causing inflammation, 11–13 oedema, ulceration and atrophy.[doi.org]
  • Pathophysiology, approaches to treatment and prophylaxis. Strahlenther Onkol 1998; 174 (Supl. 3): 82-4. [ Links ] 11. Fraser R, Frisby C, Schirmer M, Blackshaw A, Langman J, Yeoh E, et al.[scielo.isciii.es]


  • An increased understanding of the tissue response and the clinical features of radiation enteritis has led to advances in the prevention and management of this condition.[ncbi.nlm.nih.gov]



  1. Andreyev J. Gastrointestinal symptoms after pelvic radiotherapy: a new understanding to improve management of symptomatic patients. Lancet Oncol. 2007;8(11):1007-1017.
  2. Khalid U, McGough C, Hackett C, et al. A modified inflammatory bowel disease questionnaire and the Vaizey Incontinence questionnaire are more sensitive measures of acute gastrointestinal toxicity during pelvic radiotherapy than RTOG grading. Int J Radiat Oncol Biol Phys. 2006;64(5):1432-1441.
  3. Do N, Nagle D, Poylin V. Radiation proctitis: current strategies in management. Gastroenterol Res Pract. 2011;2011:917941.
  4. Kountouras J, Zavos C. Recent advances in the management of radiation colitis. World J Gastroenterol. 2008;4(48):7289–7301.
  5. Denham J, Hauer-Jensen M. The radiotherapeutic injury–a complex ‘wound’. Radiother Oncol. 2002;63(2):29-145.
  6. Lange M, Marijnen C, Maas C, et al. Risk factors for sexual dysfunction after rectal cancer treatment. Eur J Cancer. 2009;45(9):1578–1588.
  7. Theis VS, Sripadam R, Ramani V, Lal S. Chronic radiation enteritis. Clin Oncol (R Coll Radiol). 2010;22(1):70-83.
  8. Andreyev H, Davidson S, Gillespie C, et al. Practice guidance on the management of acute and chronic gastrointestinal problems arising as a result of treatment for cancer. Gut. 2012;61(2):179-192.
  9. Webb GJ, Brooke R, De Silva AN. Chronic radiation enteritis and malnutrition. J Dig Dis. 2013;14(7):350-357.

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Last updated: 2019-06-28 11:23