One of the most common causes of blood in the stool is Constipation or excessively hard stool. When you pass a piece of feces that is difficult to pass, you may scrape the wall of your anus which leads to bleeding. This is a temporary problem and should sort itself out automatically. You should be careful to wash your anus immediately and wipe it dry with a soft tissue to prevent any infection from occurring. However, this is not an alarming situation unless it repeats itself often. You can also suffer from an anal fissure which happens when a sensation of tearing is felt while defecating. The difference between this a fissure and blood caused by hard stool is that the fissure is a tear in the skin, whereas when it comes to hard stool, the skin may be scraped causing bleeding.
You may be suffering from a more serious problem such as colitis if there is blood in your stool. colitis is a condition where your colon is inflamed and could even present ulcers when an examination is done. This is an auto immune condition where your immune system attacks the healthy cells of the colon and causes the colon to get inflamed. In severe cases, ulcers could be formed, which can rupture as feces are passed through the colon. Bleeding from ulcers in the colon may also be spontaneous.
hemorrhoids can occur in the anus which will lead to blood in the stool. A hemorrhoid is when a blood vessel becomes swollen and can rupture, causing bleeding. It is not necessary that your stool will be painful when you suffer from hemorrhoid tears.
When you experience bloody stools, it is important to see the color of the blood. A bright red shade indicates that the blood has come from the lower part of the colon or the anal opening itself. If it is darker, it means that it has oxidized or mixed with digestive chemicals and is likely to have come from higher up in the tract. A darker shade of blood may be a cause of concern as it indicates bleeding that is not related to the anus or colon.
answered by M W