2. Anal fissures
Another common cause of blood in the stool is an anal fissure. The tissue that lines the anus is very thin and moist, which can make it susceptible to tears (anal fissures). Trying to pass hard stools or stools that are large in size can lead to anal fissures, as can engaging in anal sex. A telltale sign of an anal fissure is stool that is tinged with bright red blood.
It can also cause an extreme amount of pain, and lead to spasms in the muscles that surround the anus (known as the anal sphincter). Anal fissures are extremely common in infants; however, people of any age can develop them. Home remedies, such as sitz baths and increasing fiber intake, can be an effective way to treat anal fissures. They usually aren’t considered harmful; however, it may not be a bad idea to see a doctor to determine if this is the actual cause of blood in the stool