Background: Bleeding per rectum is a common problem in all ages. Colonoscopy is suggested in patients more than 50 years of age or high risk patients. The incidence of cancer in young adults is rising, as well as right-sided colon cancer. Proctoscopy to flexible sigmoidoscopy is suggested in young adults with rectal bleeding.

Objective: To determine the findings and locations of lesions from colonoscopy in young adult patients with rectal bleeding.

Materials and Methods: One year of consecutive out-patients age 18-50 years with rectal bleeding that underwent a colonoscopy after the history and physical exam were performed at Chiang Mai University Hospital. Bleeding per rectum is defined as bright red blood from the rectum, red blood in either feces, on toilet paper or in the toilet bowl. Lesions were recorded in centimeters from the anal verge. The suspected or abnormal lesions were biopsied and sent to a pathologist. Patients with inflammatory bowel disease, known history of cancer, diverticulitis, bowel ischemia or suspected bowel perforation were excluded.

Results: Forty-nine patients met the inclusion criteria and underwent colonoscopy without complications. A complete colonoscopy was performed in 45 patients (91%). A normal colonoscopy was found in 13 patients (28.8%) with hemorrhoids as the common lesion recorded for 17 patients (37.7%). The second most common finding was polyps, found in ten patients (22.2%) and all were biopsied. Four of ten patients with polyps (8.8 %) were precancerous lesions either tubulous or villous adenoma. One patient (2.3%) had a tissue mass that revealed adenocarcinoma.

The majority of adenomatous and cancerous lesions (80%) were found within 60 cm from the anal verge. Only one patient had a tubulous adenoma at 80 cm from the AV. On multivariate regression analysis, malignant and adenomatous lesions were statistically significant with age (p = 0.04, OR = 1.16, 95%CI = 1.01 to 1.34).

Conclusion: Hemorrhoids were the most common cause of rectal bleeding in adults age 18 to 50 years. Most of the lesions were found within 60 cm from AV. We concluded that a flexible sigmoidoscopy is sufficient to evaluate the cause of bleeding in a young adult with rectal bleeding. But a colonoscopy should be considered in patients with increasing age (> 40 years old). The present paper was limited by the number of patients due to time and a single institute.

Keywords: Bleeding per rectum, Young adult, Colonoscopic finding, Pre-cancerous lesions