Intestinal Peristalsis: What It Is and What Disorders Occur

We recall the word "peristalsis" when the abdomen rumbles, swells, or lets us down at an inconvenient moment. Then scary terms from the internet surface in the mind — "dyskinesia," "motility disorder," "obstruction." Let's calmly sort out what these words mean.

Peristalsis: What It Is and How It Works

Peristalsis is a wave-like contraction of the walls of hollow tubular organs that propels their contents toward the exit. The intestine does not squeeze food out in a single push: a wave runs along the wall, and it gradually moves the contents forward.

The organ wall has two layers of smooth muscle — longitudinal and circular — and their coordinated contractions create the wave. These contractions are slow and involuntary. The rhythm is set by pacemakers — clusters of nerve cells, among which interstitial cells of Cajal play the main role.

The smooth muscles of the digestive tract are involuntary: consciousness does not control the movement of food.

Intestinal Motility: What Is Considered Normal

Motility is a broader concept: it is all motor activity of the intestine, of which peristalsis is only one component. The norm differs for each section; the frequencies of waves from pacemakers are as follows: stomach — 2–4 cycles per minute, duodenum — 10–12, jejunum — 9–12, ileum — 6–8, colon — about 0.6 (plus rhythms of 3–4 and 6–12), rectum — about 3.

In the small intestine, waves travel at a speed of 0.1–0.3 cm per second: the speed is higher in the duodenum and lower in the jejunum.

Ileus: When the Intestine Does Not Work Without a Mechanical Barrier

Ileus is a condition in which the intestine does not work properly, although there is no structural cause of obstruction. Paralytic ileus, or pseudo-obstruction, is one of the main causes of intestinal obstruction in infants and children.

Intestinal Motility Disorder: Causes and Signs

Causes are divided into two groups. Mechanical: adhesions and scars after surgery, foreign bodies, hernia, fecal impaction, intussusception, tumors, volvulus, inflammatory diseases such as Crohn's disease, and rarely — gallstones.

The second group — the lumen is clear, but the intestine does not contract: gastrointestinal infections, disturbances of chemical and electrolyte balance (for example, low blood potassium), abdominal surgery, impaired blood supply to the intestine, inflammation in the abdominal cavity such as appendicitis, kidney and lung diseases, and taking certain medications, especially narcotic analgesics.

Something similar can occur higher up — in the stomach. Gastroparesis slows or stops the passage of food into the small intestine, although there is no blockage; the most common known cause is diabetes, and among the symptoms are a rapid feeling of fullness after starting to eat, a feeling of fullness long after eating, nausea, and vomiting.

Among the symptoms of obstruction and ileus are:

• bloating and distension of the abdomen, gas;
• pain and cramps in the abdomen;
• constipation or diarrhea;
• inability to pass gas;
• nausea and vomiting.

How Intestinal Function Is Assessed During Examination

They start with a conversation and examination: the doctor asks about the history of symptoms and may notice bloating, tenderness, or a hernia. Next are instrumental methods: computed tomography of the abdomen, abdominal radiography, barium enema, X-ray examination of the upper gastrointestinal tract and small intestine.

If delayed gastric emptying is suspected, studies measuring the rate of emptying are used, and complications are sought.

When to See a Doctor

Reasons: no bowel movement or gas, bloating that does not go away, repeated vomiting, unexplained abdominal pain that does not go away.

Peristalsis by itself is not a reason to call an ambulance; 103 or 112 — for a sharp deterioration in condition, severe abdominal pain, and uncontrollable vomiting.

The material is for reference: it helps to understand the terms but does not replace a doctor's consultation — it is better to discuss your complaints with a real specialist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer