OVERVIEW

What is pyloric obstruction?

The pylorus is the narrowest part of the digestive tract, with a normal diameter of about 1.5 cm, making it prone to obstruction.

Due to the obstruction of the pylorus, gastric contents cannot pass smoothly into the intestines and instead accumulate in the stomach, leading to hypertrophy of the gastric wall muscles, dilation of the gastric cavity, and inflammation, edema, and erosion of the gastric mucosa. Pyloric obstruction can occur in the early or late stages of ulcer disease.

How common is pyloric obstruction in patients?

Pyloric obstruction is the most common complication of gastroduodenal ulcers. It accounts for 10%–30% of ulcer patients treated surgically. Among ulcer patients undergoing surgery, 5%–20% develop mechanical pyloric obstruction.

What are the types of pyloric obstruction?

Based on the cause, pyloric obstruction can be classified into inflammatory-edematous obstruction, spastic obstruction, adhesive obstruction, and cicatricial obstruction.

SYMPTOMS

What are the types of pyloric obstruction?

• Inflammatory and edematous obstruction: Due to active ulcers, mucosal inflammatory edema obstructs the pyloric passage, but this symptom can be relieved once the inflammation and edema subside. This type of obstruction is temporary.

• Spastic obstruction: Ulcers located at or near the pylorus can cause reflex contraction of the pyloric circular muscle due to mucosal edema or ulceration, leading to pyloric obstruction. This obstruction is intermittent.

• Adhesive obstruction: Caused by adhesions or traction following ulcer inflammation or perforation.

• Cicatricial obstruction: A common type. Chronic ulcers lead to submucosal fibrosis, forming cicatricial stenosis that obstructs the pyloric passage, preventing food and gastric fluid from passing smoothly. This obstruction is permanent and often requires surgical treatment.

What are the manifestations of pyloric obstruction?

• Abdominal pain and bloating: Pyloric obstruction often occurs after eating, especially in the evening. Postprandial upper abdominal pain worsens, evolving into diffuse distension or discomfort as gastric retention develops.

• Vomiting: The most prominent symptom, occurring more frequently in the afternoon and evening. The severity of obstruction correlates with the frequency of vomiting.
  Vomitus contains retained food with a sour odor. Symptoms often improve or disappear after vomiting, so many patients induce vomiting voluntarily.

• Upper abdominal distension: Due to impaired gastric emptying and excessive retention of gastric contents, the stomach becomes distended. Some patients may exhibit a hemispherical bulge, representing the outline of an enlarged stomach.

• Peristaltic waves and succussion splash: Difficulty in gastric contents passing through the pylorus leads to strong gastric muscle contractions, sometimes visible as peristaltic waves moving from left to right toward the pylorus.
  On an empty stomach, gently shaking the patient's waist may produce a splashing sound of water in the stomach. About two-thirds of pyloric obstruction patients exhibit a distinct succussion splash, indicating fluid retention and poor emptying.

What are the consequences of pyloric obstruction?

• Excessive vomiting can lead to malnutrition and dehydration. Patients may exhibit dry skin, poor elasticity, weight loss, and a weak appearance. Frequent vomiting also causes significant loss of water and electrolytes, resulting in dehydration, electrolyte imbalance, and alkalosis.

• In some cases, symptoms such as limb twitching, drowsiness, muscle weakness, or even coma may occur.

CAUSES

What are the common causes of pyloric obstruction?

• Ulcers located at or near the pylorus can cause obstruction due to mucosal edema;

• Ulcers may trigger reflexive contraction of the pyloric circular muscle, leading to pyloric obstruction;

• Chronic ulcers can cause submucosal fibrosis, resulting in cicatricial stenosis.

The onset or worsening of pyloric spasms is often paroxysmal and may resolve spontaneously. Mucosal edema can subside as inflammation decreases.

Pyloric stenosis caused by scar contracture is irreversible and progressively worsens. Pyloric spasms are functional, while the other causes are organic.

Who is more prone to pyloric obstruction?

Pyloric obstruction can occur in people of all ages, especially those with poor gastrointestinal function.

Under what circumstances is pyloric obstruction more likely to occur?

Patients usually have a long history of ulcers. As the condition progresses, stomach pain gradually worsens, accompanied by symptoms such as belching and regurgitation. Pyloric obstruction is more likely to occur when antacids prove ineffective.

DIAGNOSIS

What tests are needed to diagnose pyloric obstruction?

Laboratory tests; X-ray examination; Gastroscopy; Saline load test.

• Laboratory tests: Complete blood count, blood biochemical tests, and gastric juice analysis. Benign ulcers typically show high gastric acid levels. If severe anemia and positive fecal occult blood are present, malignant ulcers should be considered.

• X-ray examination: In addition to observing a large gastric bubble under fluoroscopy, a barium meal gastrointestinal contrast study should be performed after gastric lavage. This clearly reveals gastric dilation and delayed emptying.

• Gastroscopy: Fiberoptic gastroscopy can identify pyloric spasms, mucosal edema or prolapse, cicatricial stenosis, and other pathological changes, as well as determine the size, location, and morphology of ulcers.

• Saline load test: Helps determine the presence of pyloric obstruction.

Which diseases is pyloric obstruction easily confused with?

Pyloric obstruction must be differentiated from pyloric spasms and edema caused by active ulcers, gastric cancer-induced pyloric obstruction, and obstructive lesions below the duodenal bulb.

TREATMENT

Which department should I visit for pyloric obstruction?

Gastroenterology, general surgery, or emergency department in urgent cases.

How is pyloric obstruction treated?

• Emergency surgery is generally not recommended for patients with pyloric obstruction. If the patient can resume eating after 3–5 days of gastrointestinal decompression and their condition gradually improves, it indicates relief of spasms and edema, allowing continued observation. A repeat barium meal examination may be necessary if needed.
  If decompression fails, it suggests cicatricial stenosis, requiring surgical intervention. If there is evidence of malignancy, aggressive surgery is necessary.

• Medical treatment:

• Correcting dehydration and electrolyte imbalance is the primary concern in treating pyloric obstruction, as excessive gastric acid loss often leads to varying degrees of alkalosis.
  Upon admission, normal saline can be administered first. Once urine output increases, potassium chloride solution should be added. Severe hypokalemic alkalosis may even require daily potassium chloride supplementation.
  Fluid replacement is achieved with 5%–10% glucose solution. Based on a daily basal requirement of 2500 mL, additional fluids are calculated according to gastric tube drainage and other fluid losses.
  Therefore, besides electrolyte solutions adjusted based on blood test results, the remaining fluid deficit should be supplemented with glucose solution.

• Secondly, continuous decompression helps restore the dilated stomach. Reduction of inflammation and edema allows recovery of gastric muscle tone. If the obstruction is caused by pyloric spasms or mucosal edema, dietary adjustments and ulcer medications should follow once the obstruction is relieved.

• Surgical treatment: If short-term medical therapy fails, it indicates that cicatricial contraction is the main cause of obstruction. Alternatively, if gastric ulcer (especially with suspected malignancy) is confirmed, elective surgery should be performed after inflammation and edema subside.

What types of medications are used for pyloric obstruction?

Normal saline, glucose and potassium chloride, albumin.

Should medication continue after pyloric obstruction improves?

Yes, acid-suppressing medications and other drugs for gastrointestinal ulcers should be continued.

What should be noted during hospitalization for pyloric obstruction?

• Assist doctors with examinations and treatments.

• Frequently ventilate the room to avoid worsening vomiting.

• Monitor emotional state and manage psychological stress caused by the disease.

Is follow-up necessary after discharge for pyloric obstruction?

Yes, regular follow-ups are required.

Can pyloric obstruction be completely cured?

Pyloric obstruction is entirely curable.

To ensure better recovery, patients must understand and manage their lifestyle, maintain a positive attitude toward treatment, and improve their quality of life. Family support is also crucial for care.

Can pyloric obstruction recur?

Pyloric obstruction is prone to recurrence. Poor lifestyle habits or failure to take acid-suppressing medications as prescribed can lead to relapse.

DIET & LIFESTYLE

What should patients with pyloric obstruction pay attention to in their diet?

• When ulcer disease is complicated by pyloric obstruction, the patient should rest in bed, fast, and receive intravenous fluids to maintain water, electrolyte, and acid-base balance. Anticholinergic drugs may also be used to inhibit gastric secretion and motility, delay gastric emptying, and enhance the neutralizing effect of food and antacids on gastric acid, thereby alleviating symptoms.

• In the early stages of pyloric obstruction, if symptoms improve after gastrointestinal decompression, a clear liquid diet can be introduced when partial obstruction remains and gastric retention is less than 250 ml. Complete obstruction requires fasting. Fat intake should be restricted, as patients with obstruction cannot tolerate fats.

What should patients with pyloric obstruction pay attention to in daily life?

• Strictly follow the doctor's instructions, take medications on time and in the prescribed dosage, and do not stop medication without authorization.

• Attend regular follow-up examinations to monitor the condition and potential side effects of medications.

• Patients should educate themselves about pyloric obstruction to recognize worsening symptoms and seek immediate medical attention when necessary.

After treatment for pyloric obstruction, can patients exercise?

Avoid strenuous exercise and prioritize bed rest.

How should family members care for a patient with pyloric obstruction?

Encourage the patient to take medications regularly and attend follow-up appointments; maintain the patient's hygiene and comfort; provide emotional support to ensure mental well-being.

PREVENTION

How to prevent pyloric obstruction?

• Actively prevent and treat primary diseases: The key to preventing this condition.

• Effectively treat ulcer disease to prevent spasmodic, edematous, and cicatricial pyloric stenosis leading to obstruction.