A 46-year-old woman comes to the physician for diarrhea and occasional fecal incontinence. She has had 3-4 loose stools a day and vague rectal discomfort for the last 2 months. The patient says, "I often feel a painful urge to go but only pass a small amount of mucus." She has noticed bright red blood mixed with the stool on several occasions. The patient was treated for cervical cancer with surgery and chemoradiation a year ago. She is afebrile. On examination, there is mild tenderness in left lower quadrant but no guarding or rebound. Rectal examination shows guaiac-positive brown stool. Her stool Clostridium difficile toxin polymerase chain reaction testing is negative. Rectosigmoidoscopy shows pale rectal mucosa, several serpiginous telangiectasias, and small areas of mucosal hemorrhage. Which of the following is the most likely diagnosis?

Question

A 46-year-old woman comes to the physician for diarrhea and occasional fecal incontinence.  She has had 3-4 loose stools a day and vague rectal discomfort for the last 2 months.  The patient says, "I often feel a painful urge to go but only pass a small amount of mucus."  She has noticed bright red blood mixed with the stool on several occasions.  The patient was treated for cervical cancer with surgery and chemoradiation a year ago.  She is afebrile.  On examination, there is mild tenderness in left lower quadrant but no guarding or rebound.  Rectal examination shows guaiac-positive brown stool.  Her stool Clostridium difficile toxin polymerase chain reaction testing is negative.  Rectosigmoidoscopy shows pale rectal mucosa, several serpiginous telangiectasias, and small areas of mucosal hemorrhage.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: This patient likely has radiation proctitis. Acute radiation proctitis may present with diarrhea, mucus discharge, and tenesmus (ineffectual/painful straining on defecation) during or within 6 weeks of pelvic radiation. Chronic radiation proctitis is characterized by similar symptoms occurring >9 weeks to years after radiation therapy and is more commonly associated with strictures, fistula formation, and rectal bleeding. The diagnosis is typically made after excluding other causes of colitis (eg, infection, inflammatory bowel disease, ischemia, malignancy) as symptoms can be nonspecific. Colonoscopy may show continuous lesions with pallor, friability, telangiectasias, and mucosal hemorrhage, as seen in this patient. Acute radiation proctitis is typically treated with supportive measures (eg, fluids, antidiarrheal agents); chronic cases may require sucralfate or glucocorticoid enemas. (Choices A and C) Angiodysplasia and ischemic colitis can present with hematochezia; however, these conditions are more commonly seen in patients age >60. Ischemic colitis is usually associated with abdominal pain and bloody diarrhea; angiodysplasia classically presents with painless bleeding. (Choice B) Crohn disease typically occurs in individuals age 15-40 with abdominal pain and bloody diarrhea. It is less likely in this patient as her colonoscopy does not demonstrate characteristic aphthous ulcers, cobblestoning, or skip lesions (normal bowel interrupted by areas of disease). The rectum is also commonly spared in Crohn disease. (Choice D) Clostridium difficile infection can be complicated by pseudomembranous colitis, which typically presents with watery diarrhea, abdominal pain, fever, and leukocytosis. This patient's lack of fever, negative C difficile toxin polymerase chain reaction testing, and absence of pseudomembranes (eg, raised yellow/off-white plaques scattered over the colonic mucosa) on rectosigmoidoscopy make the diagnosis less likely. pseudomembranes Educational objective: Radiation proctitis may present with bloody diarrhea, mucus discharge, and tenesmus during or months after the completion of pelvic radiation therapy. The diagnosis is typically made after excluding other causes of colitis (eg, infection, inflammatory bowel disease, ischemia, malignancy). References: Radiofrequency ablation for the treatment of radiation proctitis: a case report and review of literature. (http://www.ncbi.nlm.nih.gov/pubmed/23320051) Images in clinical medicine. radiation proctitis. (http://www.ncbi.nlm.nih.gov/pubmed/20843251)

A 46-Year-Old Woman Comes to the Physician for Diarrhea and Occasional