Using a nonabsorbable carbohydrate, Lawson (1985) showed that small bowel mean transit times were 99, 125, and 137 minutes in each trimester, compared with 75 minutes when nonpregnant. In a study cited by Everson (1992), mean tran sit time for a mercury-illed balloon from the stomach to the cecum was 58 hours in term pregnant women compared with 52 hours in nonpregnant women.
Muscular relaxation of the colon is accompanied by increased absorption of water and sodium that predisposes to consti pation. This complaint is reported by almost 40 percent of women at some time during pregnancy (Everson, 1992). Such symptoms are usually only mildly bothersome, and preventive measures include a high-iber diet and bulk-forming lxatives.
Wald (2003) has reviewed treatment options. We have encoun impacted stool. These women almost invariably had chronically abused stimulatory laxatives.
he estimated monthly prevalence of diarrhea among adults is 3 to 7 percent (DuPont, 2014). Diarrhea can be classiied as acute «2 weeks), persistent (2 to 4 weeks), and chronic (>4 weeks). Most cases of acute diarrhea are caused by infectious agents, and a third result from foodborne pathogens. The large variety of viruses, bacteria, helminths, and protozoa that cause diarrhea in adults inevitably also alict pregnant women. Some of these are discussed in Chapter 64. Evaluation of acute diarrhea depends on its severity and duration. Some indications for evaluation include profuse watery diarrhea with dehydration, grossly bloody stools, fevera> 38°C, duration >48 hours without improvement, recent antimicrobial use, and diarrhea in the immunocompromised patient (Camilleri, 2015; DuPont, 2014). Cases of moderately severe diarrhea with fecal leukocytes or gross blood may best be treated with empirical antibiotics rather than evaluation. Some features of the more common acute diarrheal syndromes and their treatment are shown in Table 54-4.
The mainstay of treatment is intravenous hydration using normal saline or Ringer lactate with potassium supplementation in amounts to restore maternal blood volume and to ensure uteroplacental perfusion. Vital signs and urine output are monitored for signs of sepsis syndrome. For moderately severe nonfebrile illness without bloody diarrhea, antimobility agents such as loperamide (Imodium) may be useful. Bismuth subsalicylate (Pepto-Bismol) may also alleviate symptoms.
TABLE 54-4. Etiology, Clinical Features, and Treatment of Common Acute Diarrheal Syndromes
Toxin producers 1-72 hr 3-4+ 1-2+ 0-1 + 3-4+, watery 1.
Staphylococcus 1. None 2.
C perfringens 2. None 3.
1-2+ 1-3+, watery, 1.
C difficile then bloody 1. Metronidazole 2.
3. Salmonella bloody 4. Campylobacter 5. Vibrio 5. Doxycycline
Severe 1-8 days 0-1 + 3-4+ 3-4+ 1-2+, bloody 6.
Shigella 6. Ciprofloxacin 7.
E coli 7. Ciprofloxacin 8. Entamoeba histolytica 8. Metronidazole
B cereus = Bacillus cereus; C difficile = Clostridium difficile; C perfringens = Clostridium perfringens; E coli = Escherichia coli.