I cannot give any concrete recommendations without personal evaluation.
A colonoscopy is generally a more comprehensive test than a sigmoidoscopy. As you know, a sigmoidoscopy only evaluates approximately 1/3 of the colon, it would not be able to tell whether the transverse colon is affected.
It is possible that the bleeding is caused by the proctitis - however without a comprehensive colonoscopy, you would never know if the ascending or transverse colon was diseased.
If you are still having symptoms, a colonoscopy would not be unreasonable.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
kevinmd_b