What Is Tenesmus?

Tenesmus is the frequent and urgent feeling that you need to poop even though your bowels are empty. It is associated with discomfort, cramping, straining, and rectal pain.

Tenesmus can be caused by a range of gastrointestinal disorders such as hemorrhoids, infections, and inflammatory bowel disease (IBD). Since it can also be a symptom of colon cancer, it's important to see a healthcare provider if you are experiencing this symptom.

This article describes the possible causes tenesmus and what your healthcare provider will do to diagnose and treat this common but often distressing symptom.

Causes of Tenesmus

The term tenesmus refers to the sensation that you need to defecate (pass a bowel movement) when you don't. Doctors don't fully understand why tenesmus occurs, but other conditions can cause changes to your body that lead to this uncomfortable and painful issue.

Conditions

Tenesmus is, essentially, a sign that your digestive system is not functioning properly. Nerve issues, inflammation, scarring of the bowel, and other problems that affect digestion and excretion are caused by a number of conditions.

The following are some common disorders that can lead to tenesmus:

• Celiac disease
• Chronic constipation
• Chronic diarrhea
• Colorectal cancer
• Crohn's disease
• Diverticular disease
• Gastroenteritis
• Irritable bowel syndrome (IBS)
• Ischemic colitis
• Pelvic floor disorders
• Prolapsed hemorrhoid
• Rectal abscess
• Rectocele
• Sexually transmitted proctitis (including gonorrhea, chlamydia, or syphilis)
• Ulcerative colitis

Radiation therapy for cervical cancer, rectal cancer, prostate cancer, or colon cancer can also cause damage and inflammation in the rectum. This can result in tenesmus as well as other symptoms such as diarrhea and pain.

Nerve Problems

It's believed that inflammation in the bowel may affect the nerves that control the excretion of waste. When these nerves are overstimulated, they may send a signal to your brain saying there's still material in the bowel.

That can trigger the muscles in the gut that are used to push out feces. Those muscles contract, so your body thinks it needs to have a bowel movement, but really there's nothing in the colon.

Bowel Damage

Another possible cause of tenesmus is scarring in the bowel brought on by severe diarrhea or constipation. When this scar tissue builds up, it makes it difficult to pass stool.

It may also cause you to feel as if there's more in the bowel than there actually is. Sores or growths around the rectum or in the colon can do the same.

Related Symptoms

You may notice other symptoms that accompany tenesmus, such as:

• Cramping
• Straining to push stool
• Rectal pain

The symptoms of tenesmus may be constantly present or may come and go.

Other problems that may occur with tenesmus, such as stomach pains and rectal bleeding, are usually related to the underlying condition that's making you to feel like you have to go to the bathroom.

Diagnosis

Your healthcare provider may recommend you see a specialist who can diagnose the cause of your tenesmus. The first step is to review your medical history, family history, and current symptoms. You should be prepared to answer questions about your bowel habits, diet, and lifestyle.

Next, your healthcare provider will conduct further tests to find the underlying reason for your symptoms.

Physical Exam

The physical exam is essential to the diagnosis of tenesmus. It helps your doctor see if there's any inflammation or abnormalities around the rectum, tenderness or pain in the abdomen, or signs of a sexually transmitted infection (STI).

The exam may involve a digital rectal exam (DRE). This involves the insertion of a gloved finger into the anus to check for hemorrhoids, blood, mucus discharge, infection, or abnormal growths.

Lab Tests

After the physical exam, your doctor will commonly order a number of blood and stool tests to help narrow down the causes.

These may include:

• Complete blood count (CBC): Shows signs of infection (characterized by an increase in white blood cells) or anemia (due to a decrease in red blood cells), among other things
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): Blood tests to look for generalized inflammation that may be associated with infections, inflammatory diseases, and other causes
• Fecal occult blood: Detects blood in a stool sample
• Stool culture: Checks for pathogenic (disease-causing) bacteria in a stool sample
• STI screening: A series of tests used to detect gonorrhea, chlamydia, syphilis, and other sexually transmitted infections
• Carcinoembryonic antigen (CEA): One of several blood tests to look for tumor markers suggestive of colorectal cancer

Imaging Studies

Before proceeding to more invasive procedures, your doctor may order imaging tests to help visualize your digestive tract.

These may include:

• Barium X-ray: A type of X-ray in which a barium enema is used to highlight growths, obstruction, lesions, or perforation (a hole) in the intestine
• Computed tomography (CT) colonography: An imaging technique involving multiple X-rays that visualize the intestines in detail, including the presence of polyps or tumors
• Magnetic resonance imaging (MRI): A type of scan using powerful magnetic and radio waves to create highly detailed images of soft tissues within the digestive tract

Procedures

If colorectal cancer is suspected or something unusual is spotted on imaging studies, your doctor may refer you to a gastroenterologist, who specializes in digestive tract conditions.

You may also need some additional tests to confirm any diagnosis:

• Colonoscopy: A procedure using a flexible scope, called a colonoscope, to examine the entire colon
• Sigmoidoscopy: A version of colonoscopy limited to the lower part of the colon, called the sigmoid colon
• Colon biopsy: Performed during a colonoscopy or sigmoidoscopy to obtain a sample of tissue for evaluation

If colorectal cancer is the cause of tenesmus, the only test that can definitively confirm the diagnosis is a biopsy. Blood tests and imaging studies can support the diagnosis, but they cannot diagnose the disease.

Tenesmus Treatment 

Tenesmus tends to improve once the underlying cause is identified and treated. Because the causes of tenesmus are so diverse, so are the treatments. Below are the treatments used for the conditions that cause tenesmus.

Summary

Tenesmus is the sensation of needing to have a bowel movement even when your colon is empty. Depending on the underlying cause, it may be accompanied by other symptoms like cramping, pain, and rectal bleeding.

The causes can range from relatively harmless, such as diarrhea or constipation, to serious, such as cancer. To determine the cause, a healthcare provider will do a physical exam, which may include a digital rectal exam. Blood tests, imaging tests, and procedures like a colonoscopy and biopsy may also be needed.

Once the cause is identified, the underlying condition needs to be treated in order for your tenesmus to go away. Many of these conditions require a change in diet, medication, or surgery to help relieve the symptoms.

A Word From Verywell

While you may feel uncomfortable discussing tenesmus with your doctor, it's important to do so. This is especially true if the symptom is persistent, worsening, or accompanied by bleeding, tarry stools, narrow stools, weight loss, fever, vomiting, or the inability to defecate. None of these symptoms should ever be dismissed or ignored.