Detecting and Treating Diseases of the Colon and Rectum

Many Americans eat an unhealthy diet and have poor toilet habits. Over the course of several years, the effect of this lifestyle can cause a person to have problems with the large bowel.

This article will describe some of the more common bowel problems.

Anatomy and physiology

The large bowel consists of the colon (5 feet long) and the rectum (8 inches long). The large bowel is connected to the small bowel at the top end and to the anal sphincters at the bottom end. The colon's main function is to process the 3 pints of liquid stool it receives each day into a manageable amount of solid stool, ready for evacuation. The rectum coordinates the process of evacuation. Normally, a person passes 150 grams of solid stool daily. The normal range of stool frequency is from 3 times per day to 3 times per week.

Functional disorders

Functional disorders are disorders in which the bowel looks normal but doesn't work properly. These are the most common problems affecting the colon and rectum. They and are not caused by any particular disease but are rather a direct result of bad diet and bowel habits.

Constipation

Constipation is defined as small, hard, difficult, or infrequent stools. Constipation is usually caused by:

• inadequate "roughage" or fiber in the diet,
• not enough fluid, or
• poor habits, especially putting off the call to stool.

Putting off evacuation causes the stool to get harder and the muscular contraction of the rectum to be less efficient. A person who is constipated will strain during a bowel movement, sometimes producing anal problems such as fissures and hemorrhoids.

Treatment of constipation includes eating more fiber and improving toilet habits. If these treatment methods don't work, laxatives are a temporary solution.

Irritable bowel (spastic colon)

Irritable bowel (spastic colon) is a condition in which the colon muscle contracts very powerfully and loses its normal coordination. The high pressure that builds up causes abdominal cramps, gas, bloating, constipation, and urgent, explosive stools.

Treatment includes avoiding caffeine, stabilizing the diet, minimizing stress, and sometimes, taking antispasm drugs.

Structural disorders

Structural disorders are those in which there is something visually abnormal that may need to be removed by surgery. The most common functional disorders are those affecting the anus (diverticular disease and cancer).

Anal disorders

Internal hemorrhoids

Internal hemorrhoids are normal structures that cushion the lower rectum and protect it from damage by stool. When they fall down into the anus as a result of straining, they become irritated and start to bleed. Ultimately, internal hemorrhoids can fall down enough to prolapse (sink or protrude) out of the anus.

Treatment includes improving bowel habits, using elastic bands to pull the internal hemorrhoids back into the rectum, or removing them surgically.

External hemorrhoids are veins that lie just under the skin on the outside of the anus. Sometimes, after straining, the external hemorrhoidal veins burst and a blood clot forms under the skin. This is called a pile and is very painful.

Treatment includes removing the clot and vein under local anesthesia in the doctor's office.

Anal fissure

An anal fissure is a split in the lining of the anus that occurs after straining. As a result, the person experiences bleeding and intense burning pain after bowel movements. The pain is caused by spasm of the internal sphincter muscle.

Fissures often get better by themselves. If they don't improve, your doctor can recommend an ointment that will relieve the pain. Surgery may be needed to help the sphincter relax.

When the tiny anal glands that open on the inside of the anus get blocked, the bacteria that always live in the glands cause an infection. When pus forms, there is an abscess (a pocket of pus). Treatment includes draining the abscess, usually under local anesthesia in the doctor's office.

Fistula-in-ano often follows drainage of an abscess. A communication (tunnel) is formed between the mouth of the gland that caused the abscess, and the skin where the abscess was drained. Fistulas cause drainage, pain, and bleeding. They rarely heal by themselves and usually need surgery.

Other perianal infections

Sometimes the skin glands near the anus get infected and need to be drained. Just behind the anus, abscesses can form in the pilonidal area.

Sexually transmitted diseases that can affect the anus include anal warts, herpes, AIDS, chlamydia, and gonorrhea.

Diverticular disease

Colonic diverticula are little outpouchings of the bowel lining that get pushed out through weak spots in the muscle of the bowel wall. They usually occur in the sigmoid colon, the high-pressure area of the bowel.

Diverticular disease is very common in Western societies, and is caused by too little roughage (fiber) in the diet. It rarely causes symptoms unless there is a complication.

Complications of diverticular disease happen in about 10% of people. They include infection (diverticulitis), bleeding, and obstruction. Surgery is needed in about half the patients who have complications.

Polyps and cancer

Cancer of the colon and rectum is a major health problem in America today.

Colorectal cancer represents a complete loss of control of the way cells grow and divide. Certain genes, responsible for maintaining control of cell growth, become mutated. This happens primarily because of prolonged exposure of colon cells to carcinogens (cancer-causing) chemicals in the stool.

When a few genes are mutated, some control is lost and precancerous polyps (adenomas) form.

Cancer can be prevented by removing these adenomas before they turn to cancer. When more genes become mutated, cell growth becomes even more out of control, and untreated adenomas may enlarge and turn to cancer.

Established cancer requires surgery and, if it is advanced, chemotherapy (and radiation for rectal cancer).

With prompt, expert treatment, most people can be cured of colorectal cancer. Hardly anyone needs a permanent colostomy (surgery to create a new opening for disposal of waste).

Because colorectal cancer arises in a benign polyp, colonoscopy can prevent colorectal cancer by finding and removing the polyps. People at special risk for colorectal cancer include those who have had polyps or cancers in the past, or those who have a history of colorectal cancer in their family.

Colitis

Colitis is a group of conditions that cause an inflammation of the bowel. There are several types of colitis,including:

• Infectious colitis
• Ischemic colitis (caused by not enough blood going to the colon)
• Radiation colitis (after radiotherapy)
• Ulcerative colitis (cause not known)
• Crohn's disease (cause not known)

Colitis causes diarrhea, rectal bleeding, abdominal cramps, and urgency. Treatment depends on the diagnosis, which is made by colonoscopy and biopsy.

Summary

Many diseases of the colon and rectum can be prevented or minimized by good diet and good bowel habits.

People who are at risk for colorectal cancer or polyps should undergo regular examinations. People who have symptoms of any of these conditions should consult their doctor without delay.

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