Digestive Health Irritable Bowel Syndrome Rectal Tenesmus Symptoms, Causes, and Treatment The Sensation of Being Unable to Empty the Bowel By Barbara Bolen, PhD twitter Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome. Learn about our editorial process Barbara Bolen, PhD Medically reviewed by Medically reviewed by Emmy Ludwig, MD on October 23, 2018 Emmy Ludwig, MD, is board-certified in gastroenterology and hepatology. She practices at the Memorial Sloan-Kettering Cancer Center in New York. Learn about our Medical Review Board Emmy Ludwig, MD Updated on April 06, 2021 Print Table of Contents View All Table of Contents Symptoms Causes Diagnosis Treatment Tenesmus is a medical term used to describe the sensation of being unable to empty your bowel after you have already defecated. Tenesmus is commonly associated with inflammatory bowel disease (IBD) but may also be caused by hemorrhoids, infections, and even cancer. Laurence Dutton / Getty Images The diagnosis may involve a stool culture, blood tests, colonoscopy, or a biopsy to identify the underlying cause. Pain medications and antispasmodics may be prescribed to help alleviate symptoms while the underlying cause is being treated. Symptoms Symptoms of tenesmus may be constant or intermittent but usually involve some or all of the following: Rectal pain Gas Bloating Cramping Itching Rectal discharge Rectal bleeding Involuntary straining When to Call a Doctor Seek medical care right away if you experience tenesmus accompanied by a high fever (over 100.4 F), chills, severe rectal bleeding, nausea, vomiting, or fainting. Is Rectal Itching a Sign of Cancer? Causes The cause of tenesmus is not well understood, but it is believed that inflammation or irritation may stimulate both somatic nerves (that transmit physical sensations) and autonomic nerves (that modulate smooth muscle contractions) in the bowel. Overstimulation of these nerves can make it feel as if there is residue within the bowel and can trigger the contractions that we recognize as the onset of a bowel movement. In addition, severe diarrhea or constipation can also cause scarring of bowel tissues. If this happens, it not only makes passing stools more difficult, but it can feel as if there is more in the bowel than there actually is. Sores or growths around the rectum or in the colon can do the same. There are numerous conditions that can trigger tenesmus, including: 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 Tenesmus can also affect people who have undergone radiation therapy for cervical cancer, rectal cancer, prostate cancer, or colon cancer (a condition referred to as radiation proctitis). Common Causes of Rectal Pain Diagnosis Tenesmus is not a medical condition but rather a symptom of a condition. As such, your doctor will want to uncover the underlying cause by first reviewing your medical history, family history, and current symptoms. This will likely include questions about your bowel habits, diet, and lifestyle. Based on these diagnostic clues, your doctor will want to perform tests to explore the more likely causes, like IBS, or exclude potentially serious ones, like rectal cancer. Physical Exam The physical exam is essential to the diagnosis of tenesmus. It helps the doctor see if there is any inflammation or abnormalities around the rectum, tenderness or pain in the abdomen, or signs of a sexually transmitted infection. The procedure 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. Serious and Benign Causes of Rectal Bleeding Lab Tests After the physical exam, the doctor will commonly order a battery of blood and stool tests to help narrow down the causes. These may include: Complete blood count (CBC): A battery of tests that can help detect infection (characterized by an increase in white blood cells) or anemia (due to decreases in red blood cells), among other things Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): Blood tests that detect generalized inflammation associated with infections, inflammatory diseases, and other causes Fecal occult blood: A test used to detect blood in a stool sample Stool culture: A test that checks for pathogenic (disease-causing) bacteria in a stool sample STD screening: A battery of tests used to detect gonorrhea, chlamydia, syphilis, and other sexually transmitted infections Carcinoembryonic antigen (CEA): One of several tumor marker tests that detects substances in blood suggestive of colorectal cancer Imaging Studies Before proceeding to more invasive procedures, the doctor may order imaging tests to help visualize the 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 of the intestine Computed tomography (CT) colonography: An imaging technique involving multiple X-rays that provide greater detail of the intestines, 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 an anomaly is spotted on imaging studies, the doctor may refer you to a gastroenterologist for an exploratory procedure to directly visualize the colon. These minimally invasive endoscopic procedures include: 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, the sigmoid colon Colon biopsy: Performed during a colonoscopy or sigmoidoscopy to obtain a sample of tissue for evaluation in the lab 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. How Colon Cancer Is Diagnosed 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 to treat tenesmus specifically in each condition. Cause Treatment Options Celiac disease Gluten-free diet Constipation Laxatives and stool softeners High-fiber diet Diarrhea Antidiarrheals like Imodium (loperamide) Colorectal cancer Opioid drugs for advanced cancer Endoscopic laser treatment Crohn's disease and Ulcerative Colitis Corticosteroids like prednisone Immunosuppressants like methotrexate Aminosalicylates like Colazal (balsalazide) TNF blockers like Humira (adalimumab) Antibiotics like Flagyl (metronidazole) Surgery Diverticular disease High-fiber diet Oral or intravenous antibiotics Surgery Gastroenteritis Antibiotics (if the cause is bacterial) Antiparastic drugs (if the cause is parasitic) IBS High-fiber diet Antispasmodics like Levsin (hyoscyamine) Anti-diarrheals or laxatives, as needed Tricyclic antidepressants like amitriptyline Ischemic colitis Antibiotics Surgery, if blood flow obstruction is severe Pelvic floor disorders Stool softeners Physical therapy Percutaneous tibial nerve stimulation (PTNS) Surgery Prolapsed hemorrhoid Rubber band ligation Sclerotherapy Hemorrhoidectomy Rectal abscess Surgical drainage Antibiotics, including penicillin Rectocele Kegel exercises Intravaginal pessary Surgery STDs Antibiotics (varies by infection) A Word From Verywell While you may feel uncomfortable discussing tenesmus with your doctor, it is 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. Was this page helpful? Thanks for your feedback! One of the most challenging aspects of having IBS is trying to figure out what's safe to eat. Our recipe guide makes it easier. Sign up and get yours now! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Petryszyn PW, Paradowski L. 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