Peristaltic Waves, Visible
With intestinal obstruction, peristalsis temporarily increases in strength and
frequency as the intestine contracts to force its contents past the obstruction. As
a result, visible peristaltic waves may roll across the abdomen. Typically, these
waves appear suddenly and vanish quickly because increased peristalsis
overcomes the obstruction or the GI tract becomes atonic. Peristaltic waves are
best detected by stooping at the patient’s side and inspecting his abdominal
contour while he’s in a supine position.
Visible peristaltic waves may also reflect normal stomach and intestinal
contractions in thin patients or in malnourished patients with abdominal muscle
atrophy.
History and Physical Examination
After observing peristaltic waves, collect pertinent history data. Ask about a
history of a pyloric ulcer, stomach cancer, or chronic gastritis, which can lead to
pyloric obstruction. Also, ask about conditions leading to intestinal obstruction,
such as intestinal tumors or polyps, gallstones, chronic constipation, and a
hernia. Has the patient had recent abdominal surgery? Make sure to obtain a
drug history.
Determine if the patient has related symptoms. Spasmodic abdominal pain,
for example, accompanies small-bowel obstruction, whereas colicky pain
accompanies pyloric obstruction. Is the patient experiencing nausea and
vomiting? If he has vomited, ask about the consistency, amount, and color of the
vomitus. Lumpy vomitus may contain undigested food particles; green or brown
vomitus may contain bile or fecal matter.
Next, with the patient in a supine position, inspect the abdomen for
distention, surgical scars and adhesions, or visible loops of bowel. Auscultate for
bowel sounds, noting high-pitched, tinkling sounds. Then, jar the patient’s bed
(or roll the patient from side to side) and auscultate for a succussion splash — a
splashing sound in the stomach from retained secretions due to pyloric
obstruction. Palpate the abdomen for rigidity and tenderness, and percuss for
tympany. Check the skin and mucous membranes for dryness and poor skin
turgor, indicating dehydration. Take the patient’s vital signs, noting especially
tachycardia and hypotension, which indicate hypovolemia.
Medical Causes
Large-bowel obstruction. Visible peristaltic waves in the upper abdomen
are an early sign of large-bowel obstruction. Obstipation, however, may be
the earliest finding. Other characteristic signs and symptoms develop more
slowly than in small-bowel obstruction. These include nausea, colicky
abdominal pain (milder than in small-bowel obstruction), gradual and
eventually marked abdominal distention, and hyperactive bowel sounds.
Pyloric obstruction. Peristaltic waves may be detected in a swollen
epigastrium or in the left upper quadrant, usually beginning near the left rib
margin and rolling from left to right. Related findings include vague
epigastric discomfort or colicky pain after eating, nausea, vomiting,
anorexia, and weight loss. Auscultation reveals a loud succussion splash.
Small-bowel obstruction. Early signs of mechanical obstruction of the
small bowel include peristaltic waves rolling across the upper abdomen and
intermittent, cramping periumbilical pain. Associated signs and symptoms
include nausea, vomiting of bilious or, later, fecal material, and
constipation; in partial obstruction, diarrhea may occur. Hyperactive bowel
sounds and slight abdominal distention also occur early.
Special Considerations
Because visible peristaltic waves are an early sign of intestinal obstruction,
monitor the patient’s status and prepare him for diagnostic evaluation and
treatment. Withhold food and fluids, and explain the purpose and procedure of
abdominal X-rays and barium studies, which can confirm obstruction.
If tests confirm obstruction, nasogastric suctioning may be performed to
decompress the stomach and small bowel. Provide frequent oral hygiene, and
watch for a thick, swollen tongue and dry mucous membranes, indicating
dehydration. Frequently monitor the patient’s vital signs and intake and output.
Patient Counseling
Discuss dietary and fluid requirements. Encourage the use of stool softeners and
increased intake of high-fiber foods for patients with chronic constipation.
Pediatric Pointers
In infants, visible peristaltic waves may indicate pyloric stenosis. In small
children, peristaltic waves may be visible normally because of the protuberant
abdomen, or visible waves may indicate bowel obstruction stemming from
congenital anomalies, volvulus, or swallowing a foreign body.
Geriatric Pointers
In elderly patients who present with visible peristaltic waves, always check for
fecal impaction, which is a common problem among those of this age group.
Also, obtain a detailed drug history; antidepressants and antipsychotics can
predispose patients to constipation and bowel obstruction.