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Introduction ⬇

Inspection of the feces is an important diagnostic tool. The quantity, form, consistency, and color of the stool should be noted. Normally, stool reflects the shape and caliber of the colonic lumen as well as the colonic motility. The normal consistency is somewhat plastic and neither fluid, mushy, nor hard. Consistency can also be described as formed, soft, mushy, frothy, or watery. When diarrhea is present, the stool is watery. Large amounts of mushy, frothy, foul-smelling stool are characteristic of steatorrhea (excess fat in the feces). Constipation is associated with hard, spherical masses of stool.

Feces have a characteristic odor that varies with diet and the pH of the stool. The odor of normal stool is caused by indole (produced in intestine by breakdown of tryptophan) and skatole (formed from decomposition of protein) formed by bacterial fermentation and putrefaction.

Normal Findings ⬆ ⬇

  1. 100–200 g/24 hr or 100–200 g/d

  2. Characteristic odor present; plastic, soft, formed; soft and bulky on a high-fiber diet; small and dry on a high-protein diet; seeds and small amounts of vegetable fiber present (as opposed to muscle fiber) (Table 4.2)

Procedure ⬆ ⬇

Collect a random, fresh stool specimen following the procedure for Collection and Transport of Random Specimens. Observe standard precautions.

Clinical Implications ⬆ ⬇

  1. Stool consistency alterations

    1. Diarrhea due to the following:

      1. Infection—Salmonella, Shigella, Yersinia, HIV enteropathy, Campylobacter, Clostridium difficile

      2. Inflammatory disorder—Crohn disease, ulcerative colitis

      3. Steatorrhea—celiac disease

      4. Carbohydrate malabsorption—lactose or sucrose deficiency

      5. Endocrine abnormalities—diabetes, hyperthyroidism or hypothyroidism, adrenal insufficiency

      6. Hormone-producing tumors—Zollinger-Ellison syndrome (pancreatic gastrin-secreting tumor leading to increased acid activity in the stomach), gastrinoma, medullary thyroid carcinoma, villous adenoma

      7. Colon carcinoma

      8. Infiltration of lesions due to lymphoma, scleroderma of bowel

      9. Drugs, antibiotic agents, cardiac medications, chemotherapy

      10. Osmotically active dietary items—sorbitol, psyllium fiber, caffeine, ethanol

      11. GI surgery—gastrectomy, stomach stapling, intestinal resection

      12. Factitious—self-induced laxative abuse associated with psychiatric disorders

    2. “Pasty” stool associated with high-fat content can be caused by the following:

      1. Common bile duct obstruction

      2. Celiac disease

      3. Cystic fibrosis—greasy “butter” stool appearance due to pancreatic involvement

    3. Bulky or frothy stool is usually due to steatorrhea and celiac disease.

  2. Stool size or shape alterations indicate altered motility or colon wall abnormalities.

    1. A narrow, ribbonlike stool suggests the possibility of spastic bowel, rectal narrowing or stricture, decreased elasticity, or a partial obstruction.

    2. Excessively hard stools are usually due to increased fluid absorption because of prolonged contact of luminal contents with colon mucosa during delayed transmit time through the colon.

    3. A large-circumference stool indicates dilation of the viscus.

    4. Small, round, hard stools (i.e., scybala) accompany habitual, moderate constipation.

    5. Severe fecal retention can produce huge, firm, impacted stool masses with a small amount of liquid stool as overflow. These must be removed manually, occasionally under light anesthesia.

  3. Fecal odor should be assessed whenever a stool specimen is collected.

    1. A foul odor is caused by dehydration of undigested protein and is produced by excessive carbohydrate ingestion.

    2. A sickly sweet odor is produced by volatile fatty acids and undigested lactose.

  4. Mucus in stool occurs in constipation, malignancy, and colitis.

Interventions ⬆

Pretest Patient Care

  1. Explain purpose of test and procedure for stool collection. Instruct the patient to refrigerate the specimen. Provide clean, dry, leakproof collection container.

  2. Advise the patient to avoid barium procedures and laxatives for 1 week before stool specimen collection.

  3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Assessment of Diarrhea and Constipation

  1. When performing a workup for the differential diagnosis of diarrhea or constipation, a patient 
history is most important. The following factors should be charted:

    1. An estimate of volume and frequency of fecal output

    2. Stool consistency and presence of blood, pus, mucus, oiliness, or bad odor in specimen; evaluate through direct observation when possible

    3. Decrease or increase in frequency of defecation

    4. Sensations of rectal fullness with incomplete stool evacuation

    5. Painful defecation

  2. Assess dietary habits and food allergies.

  3. Assess emotional state of patient—psychological stress may be a major cause of altered bowel habits.

  4. Assess for signs of laxative abuse.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed. Counsel the patient regarding abnormal findings. If the patient has watery diarrhea, note history of contact with affected family members, travel to a developing country, vacation or resort travel to areas at high risk for travelers’ diarrhea, community and municipal water supply, or contact with farm animals. Explain that additional testing (e.g., colonoscopy) may be necessary.

  2. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.