saudigastro.com/patients/gastric-outlet-obstruction
Category
Serious
Red flags
5
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
What is it?
Food leaves the stomach through a narrow muscular opening called the pylorus into the first part of the small bowel (the duodenum). In gastric outlet obstruction, this passage is narrowed or blocked, so the stomach cannot empty properly. Food and fluid stay in the stomach, causing fullness, pain and vomiting. This can lead to dehydration, loss of body salts and weight loss. It is a mechanical blockage, which is different from gastroparesis, where the stomach muscle is weak but there is no blockage.
How common is it?
It is uncommon. Today it is seen less often from ulcers than in the past, and more often from tumours of the stomach, pancreas or nearby areas.
Why does it happen?
Causes can be benign (non-cancer) or malignant (cancer). Benign causes include scarring from long-standing peptic ulcers, swelling from active ulcers, Crohn's disease, swallowed objects, and rarely a narrowing from caustic injury or a condition in babies called pyloric stenosis. Malignant causes include cancer of the stomach, pancreas, bile duct or duodenum pressing on or growing into the outlet. Finding the cause is essential because treatment differs.
Symptoms
- Vomiting, often of undigested food eaten hours or even the day before
- Feeling full quickly and bloated after small amounts of food
- Upper belly pain or discomfort, sometimes relieved by vomiting
- Nausea and loss of appetite
- Weight loss and weakness
- A splashing sound in the upper belly
Red flags — seek urgent medical care
Persistent or repeated vomiting that you cannot control
Can cause dehydration and low body salts. Go to the emergency department.
Vomiting blood or black stool
Bleeding from the stomach or duodenum. This is an emergency.
Severe, sudden or constant belly pain
May mean a complication such as perforation. Seek emergency care immediately.
Muscle cramps, weakness, confusion, very little urine, or dizziness
Signs of dehydration or salt imbalance. Needs urgent care.
Weight loss without trying, with persistent fullness
Needs prompt medical evaluation to look for the cause, including cancer.
How is it diagnosed?
The doctor examines you and checks blood tests for dehydration and salt imbalance. Upper endoscopy (a flexible camera passed through the mouth under sedation) is the key test to see the blockage and take biopsies (tiny tissue samples). A CT scan shows the stomach, pancreas and nearby structures. Sometimes a barium X-ray or a stomach-emptying test is used. If the stomach is full of fluid, it may be emptied first so that endoscopy is safe.
What the latest science says
For people with a blockage from advanced cancer, a stent (a small expandable tube placed by endoscopy) can relieve symptoms with a shorter recovery than surgery in many cases; newer techniques can also create a new passage between the stomach and bowel under endoscopic guidance. The best option depends on your health, your outlook and the available expertise.
Outlook — what to expect
The outlook depends on the cause. Blockages from healed ulcers or temporary swelling often improve a lot with treatment, while blockages from cancer need a plan from a multidisciplinary team to relieve symptoms and treat the cancer when possible.
Treatment
Habits & Lifestyle
Do not try to treat persistent vomiting at home. These steps support care while you arrange medical review.
- Seek medical care early if vomiting continues for more than a short time or you cannot keep fluids down.
- Do not use laxatives or herbal remedies to "clear" the stomach.
- Avoid smoking and alcohol.
- Do not stop prescribed medicines without advice, and avoid NSAID painkillers unless your doctor agrees.
- Keep a record of your weight and symptoms for your appointments.
Diet
Nutrition becomes hard when food cannot leave the stomach. Advice depends on how severe the blockage is, so follow your team's plan.
- You may be asked to stop eating for a while so the stomach can rest and be emptied.
- When allowed to eat, small frequent meals of soft or liquid foods are usually easier.
- Avoid foods that are hard to digest such as tough meat, raw vegetables with skins, nuts and large amounts of fibre if advised.
- A dietitian may suggest nutritional drinks or, if needed, feeding through a tube or a vein.
Medications
Medicines help symptoms and treat some causes but do not open a fixed blockage. Your doctor decides which are right.
- Fluids and salts are given through a vein to correct dehydration.
- Acid-suppressing medicines (such as PPIs) treat ulcer-related swelling.
- Antibiotics are used if H. pylori is found.
- Anti-sickness medicines may be used, but "gut-moving" medicines are avoided when there is a true blockage.
Procedures & Surgery
Opening the blockage is often needed. The choice depends on the cause, your general health and your wishes.
- A tube through the nose or mouth can drain the stomach first.
- Balloon stretching (dilation) during endoscopy can widen scar-related narrowing.
- An endoscopic stent can relieve a blockage caused by a tumour.
- Surgery can bypass the blockage or remove the diseased part, and is chosen for suitable patients.
- Treatment of the underlying cancer may involve chemotherapy, radiotherapy or surgery, planned by a specialist team.
Living with the condition
- Ask about a nutrition plan early; weight and strength affect treatment options.
- Know when to return urgently: repeated vomiting, blood, or severe pain.
- Support from family and a counsellor can help if the cause is serious.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- What is blocking my stomach outlet?
- Do I need endoscopy, a CT scan or other tests?
- Which treatment is best for me: dilation, stent or surgery?
- How should I eat and drink in the meantime?
- When should I come back urgently?
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Status: Approved for publication by SGA; individual clinician review is ongoing · Published 24/04/2026
For general education only; it does not replace your doctor’s advice. Individual clinician review of this guide is ongoing. SGA clinician? Review this guide