Abnormal discharge can occur from any region of the body. Discharges can occur either on the surface of the skin or through a body cavity. The type of discharge may vary depending on the cause. A rectal discharge is an expulsion of any abnormal solid or fluid matter from the rectum and anus. Discharge of stool from the rectum is not strictly considered to be an abnormal discharge. This is because the stool is naturally expelled through the rectum and anus every day.
Even abnormal stools that are soft and watery are not considered to be abnormal rectal discharges. Similarly, expulsion of flatus (gas) from the rectum is not considered to be an abnormal discharge. A rectal discharge includes mucus, blood, and pus. These are not the normal components of stool and flatus. Different types of rectal discharges occur due to different causes.
Read more on normal vs abnormal stool.
Types of Rectal Discharge
The following are the main types of rectal discharge that one may encounter:
Blood coming out of the rectum and anus indicates a disruption of the integrity of the blood vessels located somewhere within the digestive tract. One of the common causes is tears or ulcers in the mucosal lining of the bowels.
The presence of pus indicates an infection. Pus is composed of various components such as bacteria, dead cells, tissue fluid, breakdown products of cells, and (sometimes) blood. Pus discharge from the rectum could be from a burst abscess present in the walls of the gut.
Some amount of mucus is normally present in the bowels and the stool. The mucus is a sticky discharge that is produced by certain cells and glands within the lining of the gut. Excess mucus discharge occurs in abnormal conditions.
Feces are not strictly considered to be an abnormal rectal discharge. Anal leakage refers to seepage of tiny amounts of watery stool from the anus even when not defecating. Conditions such as bowel incontinence and fecal impaction can cause abnormal leakage of feces.
When present in small volumes, blood, mucus and pus get mixed with stool and may not be easily noticeable. The source of these discharges may not always be located inside or near the rectum. In some cases, blood, mucus and pus discharge may come from the upper gastrointestinal regions. Discharges from esophagus, stomach, and upper small intestine may eventually find their way out through the rectum.
However, these discharges may not be recognizable in their original form as they undergo degradation, digestion, and absorption during their transit through the gastrointestinal tract. For example, blood that comes from the upper reaches of the gastrointestinal tract may appear as a black, tarry mass rather than a bright red fluid.
Black colored tarry feces caused by the presence of degraded blood in the stool are technically referred to as melena. Mucus from the upper parts of the gastrointestinal tract rarely reaches the rectum without being digested or extensively mixed with other gastrointestinal contents.
Causes of Rectal Discharge
Rectal discharge can occur due to multiple causes. The most common cause of rectal discharge is an injury or inflammation in the gut. Small volumes of blood or mucus discharge may not be a medical emergency. However, a large volume of blood or mucus discharge from the rectum should be taken seriously and medical attention must be sought immediately.
Some of the potential causes of rectal discharge can be serious. Without prompt treatment, fatal complications may develop within a few hours or days. The following are some of the common reasons for rectal discharge:
Hemorrhoids (also referred to as piles) can cause discharge of both blood and mucus from the rectum. Hemorrhoids are characterized by swelling of the rectal veins. Due to the presence of tortuous and swollen rectal veins, bowel movements become very painful. A break in these blood vessels causes bleeding during bowel movements, which is usually noticed when wiping the anal area after defecation. Pre-existing hemorrhoids can be exacerbated by constipation and diarrhea.
Inflammatory bowel disease
Inflammatory bowel disease (commonly abbreviated as IBD) is an autoimmune disorder which causes inflammation of the bowels. There are two kinds of inflammatory bowel diseases: Crohn’s disease and ulcerative colitis. Crohn’s disease can affect any region of the gut. However, ulcerative colitis is mainly restricted to the lower regions of the bowels. Both blood and mucus discharges can occur due to inflammatory bowel diseases.
Irritable bowel syndrome
Irritable bowel syndrome (commonly abbreviated as IBS) is characterized by an abnormal bowel behavior accompanied by abdominal pain, diarrhea and/or constipation. Mucus discharge from the rectum is common in this condition. However, bloody discharge is very rare, and may occur if the irritable bowel syndrome is also accompanied by hemorrhoids.
Anal fissures refer to the presence of tiny tears within the lining of the anal mucosa. Diarrhea and constipation are common causes of anal fissures. However, anal fissures may also be associated with inflammatory bowel disease, anal infections, and anal cancer. The symptoms of anal fissures are similar to tha of hemorrhoids. Itching, pain, and burning sensation are present in the anal area. A bloody discharge may also be noticed while cleaning up after a bowel movement.
Proctitis refers to an inflammation of the rectum. A variety of conditions such as inflammatory bowel disease, sexually-transmitted infections, antibiotics, radiation treatment of pelvic region, and diarrhea can cause proctitis. Rectal pain, constant urge to pass feces, feeling of fullness in the rectum are common symptoms of proctitis. Mucus and blood are frequently present in the feces.
Fecal incontinence is characterized by a lack of control over the passing of feces. Consequently, small amount of feces may continue to escape from the rectum and the anus even when a person has no intention of defecating. In some cases, the entire contents of the rectum may pass out involuntarily. Acute cases of fecal incontinence are usually due to constipation or diarrhea. Chronic cases of fecal incontinence are caused by nerve or muscle dysfunction that compromises the functioning of the anal sphincters.
Gastroenteritis is caused by infections of the gut caused by viruses, bacteria, and protozoa. Acute diarrhea with mucus discharge is a common feature of gastroenteritis. Diarrheal outbreaks (referred to as stomach flu) are commonly caused by viral gastroenteritis. In some cases, extensive inflammation may also rupture the tiny blood vessels within the gut, resulting in a bloody diarrhea.
Some individuals cannot digest certain food components due to lack of appropriate digestive enzymes in their gut. Consumption of offending foods (such as lactose) by such individuals causes diarrhea and mucus discharge in the stool.