The rectum is the second-to-last part of your digestive tract, sitting just before the anus. Its main role is to store stool temporarily and then move it toward the anus for elimination. This organ plays an essential role in maintaining continence—the ability to control when and how you have a bowel movement.

When the rectum is not functioning properly, you may experience uncomfortable symptoms such as pain, constipation, fecal incontinence, or rectal bleeding. Understanding how the rectum works, its anatomy, and common conditions can help you take better care of your digestive health.

Anatomy Of The Rectum

The rectum is a muscular tube about 5 inches long, located between the colon and the anal canal. It sits in the pelvic cavity above the pelvic floor and follows the curve of the sacrum (the triangular bone at the base of the spine). Connective tissues attach the rectum to the sacrum, helping it maintain structure and support.

Rectal Wall Structure

The rectal wall is made up of five distinct layers:

  1. Mucosa – The innermost lining that secretes mucus, easing stool passage.

  2. Deep mucosa – Adds protection and elasticity.

  3. Submucosa – Contains blood vessels and lymphatics.

  4. Muscularis propria – Thick muscle layers that help push stool downward.

  5. Serosa – The outer protective layer.

Additionally, the rectum contains three folds of tissue called the valves of Houston, which act like shelves to help hold stool in place until defecation.

Rectal Ampulla

The rectum ends at the anal canal, where the wider portion, called the rectal ampulla, stores feces before evacuation. When stool fills this area, nerve signals trigger the urge to defecate.

Congenital Malformations

Some infants are born with anorectal malformations, where the rectum or anus does not develop correctly. These conditions may block stool passage and typically require surgery early in life.

What Does The Rectum Do?

The primary function of the rectum is storage and controlled evacuation of stool.

The Defecation Reflex

When stool accumulates in the rectum:

  • Stretch receptors in the rectal walls activate.

  • Nerve signals are sent to the brain, which processes the information.

  • The internal anal sphincter relaxes, signaling the urge to pass stool.

  • Once you voluntarily relax the external anal sphincter, stool passes through the anus.

This complex reflex ensures that bowel movements are controlled, helping maintain continence.

Associated Conditions

Several medical conditions can affect the rectum, ranging from mild discomfort to serious diseases like cancer.

Hemorrhoids

Hemorrhoids are swollen veins in the rectum or anus. Internal hemorrhoids form inside the rectum and can cause:

  • Rectal bleeding (bright red blood on toilet paper or stool)

  • Discomfort or itching

  • A sensation of incomplete evacuation

Risk factors include chronic constipation, straining during bowel movements, obesity, and pregnancy.

Polyps

Rectal polyps are growths on the lining of the rectum or colon. While most are benign, some can develop into colorectal cancer over time. Polyps are usually detected and removed during colonoscopy screenings.

Fecal Incontinence

This condition makes it difficult to control bowel movements. It is more common in:

  • Older adults

  • Women after childbirth (pelvic floor damage)

  • People with nerve injuries or chronic constipation

Symptoms include unexpected leakage of stool or inability to reach the toilet in time.

Inflammatory Bowel Disease (IBD)

Conditions like Crohn’s disease and ulcerative colitis cause rectal inflammation, leading to:

  • Rectal bleeding

  • Abdominal pain

  • Diarrhea

  • Weight loss and fatigue

Colorectal Cancer

Cancer can begin in the rectum or colon, often developing from precancerous polyps. Risk factors include:

  • Family history of colorectal cancer

  • Smoking

  • Inflammatory bowel disease

  • Diet high in processed meats and low in fiber

Symptoms may include bloody stools, unexplained weight loss, or persistent changes in bowel habits.

Rectal Abscesses

An abscess is a pus-filled infection near the rectum. Symptoms include:

  • Severe rectal pain

  • Swelling or redness

  • Fever

  • Pus discharge

Treatment usually involves surgical drainage and antibiotics.

Fecal Impaction

When stool becomes hardened and stuck in the rectum, it can block normal bowel movements. Fecal impaction is more common in people with chronic constipation, immobility, or neurological conditions.

Prolapsed Rectum

In this condition, the rectum slips out of its normal position and protrudes through the anus. Symptoms include:

  • A visible red lump outside the anus

  • Bleeding

  • Difficulty controlling bowel movements

Treatment ranges from dietary changes to surgical repair.

Diagnostic Testing

Doctors use several tests to examine rectal health and identify conditions:

  • Digital Rectal Exam (DRE): A gloved finger is used to feel for lumps or abnormalities.

  • Anoscopy: A small tube examines the anus and rectum for hemorrhoids or growths.

  • Colonoscopy: A flexible camera inspects the colon and rectum for inflammation, polyps, or cancer.

  • Flexible Sigmoidoscopy: Similar to colonoscopy but limited to the rectum and lower colon.

  • Defecography: X-rays track stool movement during defecation.

  • Manometry: Measures rectal and anal sphincter pressure, often used for incontinence.

  • Balloon Expulsion Test: Evaluates rectal capacity and muscle function.

Tips For Keeping Your Rectum Healthy

Maintaining rectal health requires a mix of dietary choices, lifestyle habits, and regular screenings.

Eat Enough Fiber

Adults should aim for 20–35 grams of fiber daily. Fiber-rich foods include:

  • Fruits and vegetables

  • Whole grains

  • Beans and lentils

  • Nuts and seeds

Fiber helps regulate bowel movements and prevents constipation.

Stay Hydrated

Drinking enough water softens stool, making it easier to pass. Pairing fiber + water is the most effective way to stay regular.

Exercise Regularly

Physical activity improves gut motility and reduces constipation. Even moderate exercise like walking or yoga can benefit digestion.

Avoid Straining

Straining on the toilet increases pressure on the rectum and can cause hemorrhoids or rectal prolapse. Using a footstool to elevate your legs (simulating a squatting position) may ease stool passage.

Get Screened For Colorectal Cancer

Guidelines recommend screenings starting at age 45 (or earlier if you’re high-risk). Colonoscopy not only detects cancer but also removes precancerous polyps.

Limit Risk Factors

  • Avoid smoking and heavy alcohol consumption.

  • Maintain a healthy weight.

  • Manage chronic conditions like diabetes or IBD.

A Quick Review

The rectum is the final storage area for stool before elimination. It plays a vital role in continence and healthy digestion. Problems with the rectum—such as hemorrhoids, prolapse, infections, or cancer—can significantly impact your quality of life.

Taking preventive steps like eating fiber, staying active, and undergoing regular colonoscopies can help keep your rectum healthy. If you notice persistent rectal pain, bleeding, or changes in bowel habits, consult a healthcare provider promptly.