General Health · Abdomen

Stomach Pain After Eating — Causes and When to Scan

When pain arrives, where it sits and what you ate beforehand usually narrows it down. Here is what an abdominal ultrasound finds — and the common causes it cannot see at all.

Person at a kitchen table pressing a hand to the upper abdomen beside a half finished meal

Pain that reliably follows meals is a useful symptom, because the timing and the trigger food point somewhere specific. The classic pattern — severe pain under the right ribs an hour or two after something fatty, sometimes spreading to the right shoulder blade — is gallstones, and it is the single most common finding when we scan people with this complaint.

Symptoms that need urgent care, not a booked scan

Severe abdominal pain that will not settle, pain with fever or yellowing of the skin or eyes, vomiting blood, or black tarry stools need same-day assessment — NHS 111 or A&E. Difficulty swallowing, persistent vomiting, unintentional weight loss, or a lump in the abdomen should go to your GP promptly; these are symptoms the NHS assesses on an urgent pathway.

Patterns

What the timing and location suggest

What you notice Commonly Ultrasound?
Severe pain under the right ribs 1–2 hours after fatty food, sometimes to the right shoulder blade Gallstones Yes — seen well
Burning behind the breastbone, worse lying down or bending Reflux No
Gnawing upper abdominal pain, sometimes relieved or worsened by food Ulcer or gastritis No — needs endoscopy
Bloating, cramping, changes in bowel habit, pain eased by opening bowels Irritable bowel syndrome No — but helps exclude others
Pain with bloating and diarrhoea after specific foods Food intolerance or coeliac disease No — blood tests and endoscopy
Severe pain boring through to the back, with vomiting Pancreas — needs urgent assessment Partly — urgent care first
Honestly

What an abdominal ultrasound does and does not see

Worth stating plainly, because the name misleads: an abdominal ultrasound does not examine the stomach itself. Gas-filled organs scatter sound, so the stomach, bowel and much of the gut are effectively invisible. If your symptoms point at gastritis, an ulcer, coeliac disease or IBS, a scan will not diagnose them — that is endoscopy and blood tests, arranged through your GP.

What it does see, and sees well: the gallbladder and stones within it, the bile ducts, the liver’s size and texture including fatty change, the kidneys, the spleen, the aorta, and much of the pancreas. That is a genuinely useful list — and for the fatty-food pain pattern above, it is usually the test that answers the question.

So the sensible framing is: a scan is excellent for gallbladder and liver questions, and a reasonable way to exclude those causes before pursuing a gut diagnosis elsewhere. It is not a general abdominal all-clear.

At IUS London

How the appointment runs

  1. 1
    Preparation matters hereDo not eat for four hours before an abdominal scan. Food empties the gallbladder, and a contracted gallbladder can hide stones. Water is fine, and take your usual medicines.
  2. 2
    The scanLying on your back with warm gel, sometimes rolling onto your side. We will ask you to take a deep breath in and hold — it brings the liver and gallbladder down into view. 30 minutes.
  3. 3
    What we assessGallbladder and bile ducts, liver size and texture, both kidneys, spleen, pancreas as far as bowel gas allows, and the aorta.
  4. 4
    ResultsExplained on screen as we scan, with the written report usually with you within two hours — and if your symptoms point at the gut rather than the gallbladder, the report says so.
FAQs

Your questions answered

How long do I need to fast before an abdominal scan?
Four hours without food. Water is fine and you should take your usual medication. Fasting keeps the gallbladder distended, which is what makes stones visible.
Can an ultrasound see my stomach lining?
No. Gas in the stomach and bowel blocks ultrasound, so the stomach lining is not assessed. Gastritis, ulcers and coeliac disease need endoscopy or blood tests via your GP.
Do gallstones always need surgery?
No. Stones found by chance without symptoms are often left alone. Stones causing repeated attacks are usually treated by removing the gallbladder — a decision for a surgeon, informed by how much they affect you.
Could it be my pancreas?
Severe pain boring through to the back with vomiting needs urgent assessment rather than a booked scan. Ultrasound sees part of the pancreas, but bowel gas often obscures it, and CT is the better test when the pancreas is the main question.
My scan was normal but I still have pain. What now?
That genuinely narrows things: gallbladder, liver, kidney and aortic causes are much less likely. The next step is usually your GP considering reflux, ulcer disease, coeliac or IBS, which need different tests.
Should I have the urinary tract scanned too?
If your symptoms include urinary changes or flank pain, a combined abdominal and urinary tract scan covers both in one appointment. Mention it when you book and we will advise which is appropriate.
Related

Where to go from here

ScansWhat a Stomach Ultrasound Shows

What the scan covers, and what the name gets wrong.

Read the guide →KidneysFlank Pain and Kidney Stones

What causes loin pain and which test finds a stone.

Read the guide →CompareUltrasound vs MRI vs CT

What each scan sees best, and which suits your question.

Read the guide →

Answer the gallbladder question first

Gallbladder, bile ducts, liver, kidneys, spleen, pancreas and aorta assessed in one 30-minute appointment — explained on screen as we scan, with the written report usually within two hours for your GP.

From £159
General abdominal scan

Abdominal scan

5a Lucerne Mews
Kensington, London W8 4ED
3 mins from Notting Hill Gate

This article is general information about abdominal pain, not individual medical advice. Severe unremitting pain, fever with jaundice, vomiting blood or black stools need same-day assessment — see NHS guidance on stomach ache and gallstones. Ultrasound does not assess the stomach lining or bowel; we do not offer endoscopy, blood tests or CT.

Written and clinically reviewed by the HCPC-registered sonographers who perform this scan at IUS London — a CQC-registered diagnostic ultrasound clinic (Provider ID 1-2775844974). Your own findings are explained to you at the scan and set out in your report.

Author: Yianni Kiromitis, Senior Sonographer, HCPC RA38415 — over 20 years’ experience in NHS and private ultrasound
Medically reviewed: 9 August 2026