ELDER TIP Older patients may ignore bowel symptoms, believing that they result from constipation, poor diet, or hemorrhoids. Evaluate your older patient's responses to your questions carefully.
On the right side of the colon (which absorbs water and electrolytes), early tumor growth causes no signs of obstruction because the tumor tends to grow along the bowel rather than surround the lumen, and the fecal content in this area is normally liquid. It may, however, cause black, tarry stools; anemia; and abdominal aching, pressure, or dull cramps. As the disease progresses, the patient develops weakness, fatigue, exertional dyspnea, vertigo and, eventually, diarrhea, obstipation, anorexia, weight loss, vomiting, and other signs or symptoms of intestinal obstruction. In addition, a tumor on the right side may be palpable.
On the left side, a tumor causes signs of an obstruction even in early stages because in this area stools are of a formed consistency. It commonly causes rectal bleeding (in many cases ascribed to hemorrhoids), intermittent abdominal fullness or cramping, and rectal pressure. As the disease progresses, the patient develops obstipation, diarrhea, or “ribbon” or pencil-shaped stools. Typically, he notices that passage of stools or flatus relieves the pain. At this stage, bleeding from the colon becomes obvious, with dark or bright red blood in the feces and mucus in or on the stools.
With a rectal tumor, the first symptom is a change in bowel habits, in many cases beginning with an urgent need to defecate on arising (morning diarrhea) or obstipation alternating with diarrhea. Other signs are blood or mucus in stools and a sense of incomplete evacuation. Late in the disease, pain begins as a feeling of rectal fullness that later becomes a dull, and sometimes constant, ache confined to the rectum or sacral region.
Diagnosis
Only a tumor biopsy can verify colorectal cancer, but other tests help detect it:
❑Digital rectal examination can detect almost 15% of colorectal cancers.
❑Fecal occult blood test can detect blood in stools. However, it's commonly negative in patients with colon cancer.
❑ Proctoscopy or sigmoidoscopy can detect up to 66% of colorectal cancers.
❑ Colonoscopy permits visual inspection (and photographs) of the colon up to the ileocecal valve, and gives access for poly-pectomies and biopsies of suspected lesions.
❑ Computed tomography scan helps to detect areas affected by metastasis.
❑ Barium X-ray, using a dual contrast with air, can locate lesions that are undetectable manually or visually. Barium examination should follow endoscopy or excretory urography because the barium sulfate interferes with these tests.
❑Carcinoembryonic antigen, though not specific or sensitive enough for early diagnosis, is helpful in monitoring patients before and after treatment to detect metastasis or recurrence.
Treatment
The most effective treatment of colorectal cancer is surgery to remove the malignant tumor and adjacent tissues and any lymph nodes that may contain cancer cells. The type of surgery depends on the location of the tumor:
❑Cecum and ascending colon — right hemicolectomy (for advanced disease) may include resection of the terminal segment of the ileum, cecum, ascending colon, and right half of the transverse colon with corresponding mesentery
❑ Proximal and middle transverse colon — right colectomy to include transverse colon and mesentery corresponding to midcolic vessels, or segmental resection of transverse colon and associated midcolic vessels
❑ Sigmoid colon — surgery is usually limited to sigmoid colon and mesentery
❑ Upper rectum — anterior or low anterior resection (newer method, using a stapler, allows for resections much lower than were previously possible)
❑ Lower rectum — abdominoperineal resection and permanent sigmoid colostomy.
Chemotherapy is indicated for patients with metastasis, residual disease, or a recurrent inoperable tumor. Drugs used in such treatment commonly include fluorouracil with leucovorin, irinotecan, and oxaliplatin.
Radiation therapy induces tumor regression and may be used before or after surgery or combined with chemotherapy, especially fluorouracil.
Special considerations
Before surgery:
❑Monitor the patient's diet modifications, laxatives, enemas, and antibiotics — all used to clean the bowel and to decrease abdominal and perineal cavity contamination during surgery. If the patient is having a colostomy, teach him and his family about the procedure:
❑Emphasize that the stoma will be red, moist, and swollen and that postoperative swelling will eventually subside.
❑Show them a diagram of the intestine before and after surgery, stressing how much of the bowel will remain intact. Supplement your teaching with instructional aids. The patient can benefit from a consultation with an enterostomal therapist or wound and ostomy care nurse. Also arrange a postsurgical visit from a recovered ostomate.
❑Prepare the patient for postoperative I.V. infusions, nasogastric tube, and indwelling urinary catheter.
❑Discuss the importance of performing deep-breathing and coughing exercises.
After surgery:
❑Explain to the patient's family the importance of their positive reactions to the patient's adjustment. Consult with an enterostomal therapist, if available, to help set up a regimen for the patient.
❑Encourage the patient to look at the stoma and participate in its care as soon as possible. Teach good hygiene and skin care. Allow him to shower or bathe as soon as the incision heals. If appropriate, instruct the patient with a sigmoid colostomy to do his own irrigation as soon as he can after surgery. Advise him to schedule irrigation for the time of day when he normally evacuated before surgery. Many patients find that irrigating every 1 to 3 days is necessary for regularity. If flatus, diarrhea, or constipation occurs, eliminate suspected causative foods from the patient's diet. He may reintroduce them later.
❑After several months, many patients with sigmoid colostomies establish control with irrigation and no longer need to wear a pouch. A stoma cap or gauze sponge placed over the stoma protects it and absorbs mucoid secretions.
❑Before achieving such control, the patient can resume physical activities, including sports, provided that there's no threat of injury to the stoma or surrounding abdominal muscles. However, he should avoid heavy lifting because herniation or prolapse may occur through weakened muscles in the abdominal wall. A structured, gradually progressive exercise program to strengthen abdominal muscles may be instituted under medical supervision.
❑If appropriate, refer the patient to a home health agency for follow-up care and counseling. Suggest sexual counseling for male patients; most are impotent after an abdominoperineal resection.
❑Anyone who has had colorectal cancer is at increased risk for recurrence and should have yearly screening and testing.
Pictures
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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