Hello - thanks for asking your question.
This presentation is absolutely not normal. There are many causes of lower GI bleeding, including cancer, polyps, diverticulosis or hemorrhoids. Anti-inflammatories, even with COX-2's such as Celebrex, are associated with bleeding.
A colonoscopy would be the most reasonable test to suggest. This is the most direct and comprehensive test to evaluate any colorectal disorders that can cause the bleeding.
If there is continued pain and the colonoscopy is negative, I would also inquire about an abdominal CT scan.
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.
Thanks,
Kevin, M.D.