22 Nausea and/or Vomiting Without Abdominal Pain
Chronic nausea and vomiting are not uncommon in primary care practice. Approximately 3% of the population has reported nausea once a week, and 2% reported vomiting at least once a month. The cost of acute gastrointestinal infections in the United States is thought to exceed $3.4 billion per year. Nausea is a vague, unpleasant sensation; it may herald the onset of vomiting or occur without vomiting. Vomiting is the forceful expulsion of gastric contents through the mouth and must be differentiated from regurgitation. The latter is an effortless backflow of small amounts of ingested food or liquid during or between meals or feedings. Dribbling of milk from a child’s mouth is an example of regurgitation. When a patient complains of vomiting, it is helpful for the physician to distinguish acute from chronic and cyclic vomiting.
The most common cause of acute nausea and vomiting in adults and children is gastroenteritis. Other common causes are gastritis, migraine, excessive alcohol ingestion, certain drugs, motion sickness, and (in children) otitis media. Common causes of chronic nausea and sometimes vomiting include pregnancy, gastritis, drugs (especially narcotics, codeine, digitalis glycosides, antiarrhythmics, salicylates, nonsteroidal anti-inflammatory drugs [NSAIDs], theophylline, chemotherapeutic agents, and antibiotics), uremia, and hepatic failure. Recurrent nausea that occurs without vomiting is often a reaction to environmental or emotional stresses. This form of nausea is temporally related to the stressful period and usually disappears when the stress is removed.
In children (as well as adults) it is important to get a complete history that should include when vomiting started and any associated symptom or precipitating factors, the nature of emesis, the characteristics of vomitus, the frequency and forcefulness of vomiting, hydration status, ingestion of medications or poisons, and family history of gastrointestinal (GI) disease. In neonates, vomiting with the first feeding suggests esophageal or intestinal atresia or some other congenital GI anomaly (e.g., malrotation, Hirschsprung’s disease). Abnormalities of the oropharynx, sepsis, metabolic disorders, and necrotizing enterocolitis can cause vomiting in the newborn. The most common causes of vomiting in the first year are gastroesophageal reflux, GI infection, urinary tract infection (UTI), dietary protein intolerance or allergies, and septicemia. When projectile vomiting occurs in infants younger than 3 months (usually ages 2 to 3 weeks), pyloric stenosis must be considered. Although it is uncommon, recurrent vomiting of bile-stained material in neonates may indicate intestinal obstruction due to atresia, stenosis, or volvulus of the small bowel.
The most common causes of vomiting in children are viral and bacterial infections, high fevers of any cause, and otitis media. Otitis media has its highest incidence in young children and may manifest as unexplained vomiting and fever. Cyclic vomiting, with or without typical migraine symptoms, may be caused by abdominal migraine, which is more common in children. Cyclic vomiting syndrome is itself an entity characterized by periods of intense vomiting lasting less than a week (three or more episodes per year) with symptom-free intervals in between. It is thought to be related to a mitochondrial DNA mutation and has several triggers, including infection, stress, motion sickness, lack of sleep, menstruation, exhaustion, and certain foods, such as monosodium glutamate, cheese, and chocolate.
In adults the common causes of acute nausea or vomiting are gastritis (alcohol or drug induced), viral gastroenteritis, psychogenic conditions, and, occasionally, labyrinthine disorders. Common viral pathogens include rotavirus, adenovirus, and norovirus. Nausea and vomiting can also be the presenting symptoms in patients with hepatitis, myocardial infarction, and diabetic ketoacidosis. Chronic vomiting in adults usually results from gastritis, mechanical obstruction, gut motility disorders (including diabetic gastroparesis), achalasia, drugs, labyrinthine disorders, and uremia. Hyperemesis gravidarum may cause chronic vomiting during pregnancy. Both food contamination and chemical poisoning must be considered as causes of vomiting, particularly if several people are affected at the same time; in cases of food poisoning, more than one person is usually experiencing symptoms. Toxins from Staphylococccus aureus or Bacillus cereus are often implicated in gastroenteritis from poorly prepared or stored foods. Nausea and vomiting of pregnancy must be considered in women of reproductive age; some pregnant women experience morning sickness in the first trimester of pregnancy, often before they are aware of their pregnancy.
Self-induced vomiting should be suspected in patients with anxiety, depression, or eating disorders, such as anorexia and bulimia. If these patients are questioned carefully, they may admit to a feeling of nausea, which they attempt to relieve by gagging themselves to produce vomiting. If an elderly patient presents with persistent vomiting, gastric or intestinal obstruction secondary to neoplasm should be suspected.
When vomiting is painless or has preceded abdominal pain by a considerable period, a surgical lesion is unlikely. Repeated episodes of unexplained vomiting and nausea may indicate pancreatitis, which is not always associated with abdominal pain. Persistent vomiting without any bile staining is an indication of pyloric obstruction. In children this may be caused by pyloric stenosis, and in adults, by ulcer scarring or tumor. Vomiting or regurgitation of undigested food indicates esophageal obstruction. Vomiting secondary to increased intracranial pressure (ICP) is often projectile and not preceded by nausea.
Nausea and vomiting are frequent manifestations of digitalis toxicity. These symptoms are not necessarily from high serum levels of the digitalis glycoside; a GI adverse effect of the drug may occur at normal serum levels. Although many patients with gastritis have abdominal pain, some patients experience unexplained nausea or vomiting without pain. Substance abuse (alcohol, caffeine, and drugs) may also be associated with unexplained nausea or vomiting. Prolonged use of marijuana can cause chronic nausea, which is often relieved with a hot shower.
When children vomit more than four times per hour, cyclic vomiting due to abdominal migraine is probable. It usually occurs a few times a month. Chronic vomiting once or twice an hour that occurs around 30 times a month is usually caused by peptic or infectious GI disorders.
The timing of vomiting may be of diagnostic importance. Patients with uremia, pregnant women, and chronic alcoholics often experience early-morning nausea and vomiting. Vomiting immediately before food is ingested may be a manifestation of anxiety, depression, or an eating disorder, whereas vomiting shortly after eating may be a consequence of gastric outlet obstruction caused by a pyloric channel ulcer, adenocarcinoma, or other infiltrative lesions.
Postprandial vomiting may also be of functional origin, although organic gastric disease should be suspected. The Rome III criteria define three separate entities of functional nausea and vomiting: chronic idiopathic nausea, cyclic vomiting syndrome, and functional vomiting. Criteria for these entities are presented in the table “Differential Diagnosis Nausea and/or Vomiting without Abdominal Pain” at the end of the chapter. Vomiting soon after eating occurs frequently in patients with gastritis and those with digitalis toxicity. Vomiting that begins 20 to 40 minutes after meals suggests gastric atony associated with diabetes, prior gastric surgery, or peritonitis. If vomiting begins 1 to 2 hours after a meal, disease of the biliary tract or pancreas may be the cause. In these latter instances, pain is usually not relieved by vomiting. Recurrent vomiting that occurs 1 to 4 hours after eating may be due to gastric or duodenal lesions causing gastric outlet obstruction. Vomiting that follows and relieves an episode of epigastric pain is usually caused by an intragastric lesion or pyloric spasm.
The odor of vomitus may also provide a clue to the cause. If the vomitus lacks the pungent odor of gastric acid, a dilated esophagus (possibly from a stricture or achalasia) may be the cause. Patients with this condition frequently vomit in the morning and vomit or regurgitate undigested food. If vomitus has a fecal odor, intestinal obstruction or a gastrocolic fistula should be suspected.