Frequent bowel movements can give key insight into the status of our organism. As we have seen already, it can be dependent on the types of foods we eat and drink, underlying pathological processes or even suggest that we have a significant health concern to get checked out. Not only is the frequency something that could be a potential early warning sign of something going wrong, bleeding during your defecation can also suggest that there is something going wrong. Here, we will explore some of the potential causes of anal bleeding after a bowel movement and what steps you need to take in order to relieve this problem.
To try to dispel some of your worries from the start, by far, the most common reason that you will be suffering from rectal bleeding following a bowel movement is from a noncancerous source. About 80 percent of all rectal bleeding stems from hemorrhoids. This is a benign inflammation of the anal mucosa usually caused by dense stools. It is something so common that it is believed that about 50 percent of the global population will suffer from this condition at some point in their life. This is probably a gross underestimation of the true prevalence rates but you can easily understand that this is something quite common in populations .
The reason that you may suffer from this condition stems mainly from the diet we eat. Diets with poor ingestion of vegetables and fruits or fiber allow stools to become more compact. The additional straining that you may need to put forth in order to help push out the fecal material is what can cause this irritation of the anal canal .
Some of the most common symptoms to watch out for include anal bleeding that will be bright red in color and potentially a great deal of pain. Why pain can be present or absent depends entirely on where these hemorrhoids are localized along your anal canal. If you find that you have painful anal bleeding, your hemorrhoids are probably in the lower part of the anal canal. These are termed external hemorrhoids. If there is bleeding but it is painless, these will be called internal hemorrhoids. 
Most of the time, this bleeding will resolve on its own so there is no urgent medical attention that is necessary. The best way to treat the condition is to ingest fiber to help stools pass more easily along the anal canal without the need to strain too aggressively. 
Although hemorrhoids are quite common, these are typically seen in populations over the age of 50. This does not account for causes of anal bleeding in younger populations. What could be more likely in this population would be some type of dermal abrasion around the rectum. This is a very broad term and can describe a number of different pathologies so I will elaborate on a few of them to consider now.
Firstly, toilet paper can be very coarse for our sensitive skin around the anal canal opening so something as simple as cleaning ourselves after defecation is something that can lead to bleeding. This will typically be just a few drops of blood on the toilet paper. The easiest way to manage this is to buy softer sheets of toilet paper to be less traumatic for our skin. If you have frequent bowel movements, the use of toilet paper multiple times a day can lead to skin irritation as well.
Another potential and more worrisome cause of dermal abrasions could be from some type of tissue growth along the anal canal. What is common in the younger population could be from an infection of HPV. This virus is one of the most common sexually transmitted diseases and will manifest as warts around the rectum . This can lead to bleeding and can be quite problematic if they are not taken care of properly. The best way to ensure protection is to receive an HPV vaccination . They are free in most countries around the world and can help protect against serious forms of cancer.
As we climb our way up the severity rankings in terms of causes of anal bleeding after a bowel movement, easily the most worrisome when there is a profound amount of rectal bleeding would be from a tumor along the intestinal tract. Colorectal cancer is a relatively common form of cancer that is also one of the most deadly so it is important to go to your doctor immediately if you notice any type of blood in your stools. Surgery and chemotherapy are your best shot at prolonging your life if you are diagnosed with the disease but the best way to protect against it would be through screening efforts. 
If you have a family history of the disease, you may have to start screening yourself at a younger age but in most countries around the world, screening colonoscopies begin at the age of 50. As unpleasant as having a tube inserted in your rectum may be, I promise you the chemotherapy and surgery you may have if you don't catch this cancer earlier are much worse so ask your family doctor what his recommendations are for screening against colon cancer and make sure you are proactive against this form of cancer.