Anal Fissures - a tear or ulcer in the lining in the last part of the rectum before the anus (anal canal). Anal fissures are not life-threatening, but can be scary because people typically learn that they have anal fissures when they see blood on the toilet paper or red poop (Hematochezia).
The most common anal fissure symptoms is red or bloody stool, accompanied by blood on the toilet paper. It is a scary and vivid symptom. Other symptoms can be itching, painful passing of stool and a feeling of irritation. Chronic anal fissures can cause quite a bit of discomfort.
Anal fissures can be caused by constipation or from straining during difficult bowel movements. In some cases anal fissures occur during childbirth, after anal sex, or ulceration of hemorrhoids. There are a number of gastrointestinal (GI) problems that cause anal fissures like Crohn's disease or Ulcerative Colitis.
The colon and rectum have many blood vessels surrounding them. The reason there are so many blood vessels is that the colon is very good at extracting nutrients from foods that have been digested, but still have nutrients in them by the time they get to the colon. Some of the nutrients that get absorbed in the colon, end up making their way into the rest of the body via these blood vessels. The problem with these blood vessels is that they make the area of the anus very sensitive and prone to injury and problems such as anal fissures.
Simple fissures go away on their own, but chronic anal fissures or acute fissures have treatments that focus on decreasing pressure on the anal canal by making sure stools are soft: