Abstract & Commentary
Synopsis: Rectal bleeding is quite common in patients younger than 50 years of age, but evaluation by total colonoscopy has often been reserved for older patients since serious lower GI lesions are thought to be unusual in younger individuals.
Source: Wong RF, et al. J Fam Pract. 2004;53(11):879-884.
Up to one fifth of patients between 20 and 40 years of age have a history of hematochezia. This study included consecutive patients younger than age 50 who underwent colonoscopy for rectal bleeding at the Salt Lake City VA Hospital or the University of Utah Medical Center between March 1997 and November 1999 (excluding known colitis, colon cancer or polyps, severe bleeding, unexplained weight loss over 5 pounds, and strong family history of colorectal cancer). In this study, 223 patients were included, and 48 (21.5%) had normal findings. Abnormalities in the remaining 71.5% included hemorrhoids in 135 patients (60.5%) with other anorectal diseases in 14 (6.3%). Twenty six patients (11.6%) had colon neoplasia including adenomatous polyps (9.9%) or cancer. Adenocarcinoma was found in 4 patients (1.8%), all in the rectum or sigmoid colon. Biopsy-proven colitis was found in 13 patients (5.8%), diverticulosis was identified in 19 patients (8.5%). Two patients had colonic angiodysplasia.
Wong and associates assert that complete colonoscopy is appropriate in patients younger than 50 who present with rectal bleeding. Other studies have demonstrated over 20% of such individuals with significant lesions. However, others have argued that colonoscopy in younger patients is not cost effective (eg, cost-effectiveness of colonoscopy at age 25 was more than $270,000 per year of life gained). Wong et al argue that flexible sigmoidoscopy may be inadequate to define all significant pathology in young patients with rectal bleeding.
Comment by Malcolm Robinson MD, FACP, FACG
Without a much larger controlled trial of colonoscopy vs some alternative intervention in young patients with hematochezia, the correct approach will remain at issue. Most clinicians will try to use all available findings on history, physical examination, and pertinent laboratory data to select the best approach to diagnosis in younger patients who bleed rectally. As a gastroenterologist, I must admit being likely to proceed with colonoscopy in most patients who are referred with rectal bleeding regardless of age. Primary care physicians might quite reasonably be more reluctant to advise such assessments when otherwise healthy young people present with hematochezia. Wong et al of the small Utah study certainly understand that their data cannot really answer our questions about management of these younger patients. Nevertheless, they are to be commended for addressing the issue and reminding us that rectal bleeding in individuals younger than 50 years of age can indicate serious disease.
Dr. Robinson, Emeritus Clinical Professor of Medicine, University of Oklahoma College of Medicine Oklahoma City, OK, is Associate Editor of Internal Medicine Alert.