Hi,
Thanks for using the XXXXXXX I am happy to address your questions, blood in the stool is not always visible, rectal bleeding has many causes. The best action you can take now, to advocate for him, is to pay attention to this symptom and be prepared to discuss it with your doctor. Many things can cause blood in the stool, ranging from abrasive toilet paper or redness in toilet water to a large, bleeding polyp. Like the lining of your mouth or nose, the lining of the colon is very vascular and has a healthy blood supply. Hemorrhoids (piles) are a common, mostly benign problem. They are the most common cause of bright red blood smears on the toilet paper or in the toilet water. Inflammatory processes in the colon, such as irritable bowel disease (IBD), irritable bowel syndrome (IBS), ulcerative colitis (family history) or diverticular disease, can cause bright red or dark red blood in the stools. Colon polyps can and do bleed at times, especially following a colonoscopy or biopsy. However, sometimes the larger ones can bleed, which may require a colonoscopy for investigation and removal of the polyp. Untreated polyps can lead to colon cancer. Constipation and straining to pass a large bowel movement can lead to smears of bright red blood on the toilet paper. Not drinking enough water, low-fiber diets and a lack of exercise can lead to constipation. Let your doctor know if you are straining to pass bowel movements. This straining can lead to tiny, uncomfortable tears in your anal tissues, called fissures. Your doctor will complete a physical exam to look for any overt causes of the rectal bleeding (hemorrhoids, anal abrasion) and obtain a medical history. Also may ask for tests to further investigate the cause, complete blood count to determines how much blood he may have lost, re-do fecal occult blood test (FOBT) to checks for the presence of blood in the stool, colonoscopy to take a look inside the colon. This test allows the doctor to see, and possibly remove, bleeding polyps from the lining of the colon or sigmoidoscopy similar to a colonoscopy, but allows the doctor to see only the final portion of the colon, including the sigmoid colon and the rectum. X-rays of the lower intestinal tract may show any large deformities of the colon. Following the test(s), your doctor will discuss the findings with you, potentially order further testing if abnormalities are found or develop a treatment plan, as needed. Hope I have answered your query. If you have any further questions I will be happy to help. Thanks

---