Bad Stomach Ache: Common Causes and What the Research Says

Bad Stomach Ache: Common Causes and What the Research Says

Published: 10 August 2026

Author: Etherys Research Team

Target URL: etherys.co.uk/blogs/news/bad-stomach-ache-common-causes

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A bad stomach ache can be alarming — especially when it comes on suddenly or doesn't go away. "Bad stomach ache" is searched 2,400 times a month in the UK, with "bad stomach ache after eating" adding another 1,300. Yet most online resources either dismiss it as "probably just gas" or jump straight to worst-case scenarios.

This article covers the most common causes of severe stomach pain, how to tell them apart, and when to seek medical attention.

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What counts as a "bad" stomach ache?

A bad stomach ache is pain that:

  • Is severe enough to stop you doing normal activities
  • Lasts more than a few hours
  • Keeps coming back over days or weeks
  • Is accompanied by other symptoms (fever, nausea, changes in bowel habits)

The location of the pain matters. Pain in the lower right abdomen could indicate appendicitis. Pain in the upper abdomen after meals could indicate gallbladder issues. Generalised cramping is more likely to be gut-related [1].

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The most common causes of a bad stomach ache

1. Food intolerance or sensitivity

Bad stomach ache after eating is one of the most common symptoms of food intolerance. Unlike a food allergy (which involves the immune system and can be life-threatening), an intolerance affects digestion. The most common triggers are [2]:

  • **Dairy** — lactose intolerance affects approximately 5% of UK adults, with higher rates in certain ethnic groups [3]
  • **Gluten** — non-coeliac gluten sensitivity causes stomach pain, bloating, and fatigue in sensitive individuals
  • **High-FODMAP foods** — onions, garlic, beans, and certain fruits can trigger pain in people with IBS
  • **Spicy or fatty foods** — these can irritate the gut lining or cause rapid gut contractions

A 2017 study by Staudacher et al. in *Gastroenterology* found that a low-FODMAP diet reduced stomach pain in 50–80% of IBS patients [4].

2. Gastroenteritis (stomach bug)

Viral gastroenteritis causes severe stomach cramps, diarrhoea, and sometimes vomiting. Most cases resolve within 2–5 days. The pain is typically cramping and diffuse (spread across the abdomen) rather than localised to one spot [5].

3. Irritable Bowel Syndrome (IBS)

IBS affects approximately 10–15% of UK adults and is one of the most common causes of recurrent bad stomach aches. IBS pain is typically:

  • Crampy in nature
  • Related to bowel movements (often relieved by going to the toilet)
  • Worse after eating
  • Associated with bloating and changes in bowel habits [6]

4. Menstrual pain

For women, menstrual cramps can cause severe lower abdominal pain that's often mistaken for a stomach ache. A 2019 study by Armour et al. in *BMJ Open* found that 71% of women aged 18–45 reported menstrual pain severe enough to affect daily activities [7].

5. Gut microbiome imbalance

After antibiotics, illness, or a period of poor diet, the gut microbiome can become depleted. This can cause increased sensitivity to food, bloating, and pain. A 2018 study by Hjørne et al. in *Gut* found that dietary fibre intake was the strongest predictor of gut microbiome recovery [8].

6. Stress and anxiety

The gut-brain connection is well-established. Stress can cause real, physical stomach pain through increased gut sensitivity and altered motility. A 2018 review by Vanuytsel et al. confirmed that psychological stress is a significant contributor to functional gut disorders [9].

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Bad stomach ache after eating: what it means

If the pain consistently follows meals, the most likely causes are:

1. Food intolerance — particularly dairy, gluten, or FODMAPs

2. Gallbladder issues — especially if pain is in the upper right abdomen after fatty meals

3. Gastritis — inflammation of the stomach lining, often triggered by alcohol, NSAIDs (ibuprofen), or stress

4. Overeating — the stomach stretches beyond comfortable capacity, causing genuine pain

5. Acid reflux — can cause upper abdominal pain alongside heartburn

If "bad stomach ache after eating" happens regularly for more than 2 weeks, see your GP to rule out gallbladder issues, ulcers, or food intolerances [1].

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When to seek urgent medical attention

See your GP urgently or call 111 if you experience [1]:

  • Severe pain that comes on suddenly
  • Pain accompanied by vomiting blood or blood in stool
  • Pain with high fever
  • Pain that makes the abdomen rigid to touch
  • Pain with difficulty breathing
  • Pain during pregnancy
  • Pain with yellowing of skin or eyes (jaundice)

Do not ignore these symptoms. Severe acute abdominal pain can indicate appendicitis, gallstones, bowel obstruction, or other conditions requiring urgent treatment.

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What helps a bad stomach ache

For immediate relief

  • **Drink warm water or peppermint tea** — peppermint has antispasmodic properties and can relax gut muscles. A 2019 review in *BMC Complementary Medicine and Therapies* found peppermint oil effective for IBS-related pain [10]
  • **Use a hot water bottle** — warmth increases blood flow and relaxes cramping muscles
  • **Avoid eating for 1–2 hours** — give your digestive system a rest
  • **Gentle movement** — a short walk can help move gas through the system

For recurring stomach aches

  • **Keep a food diary** — track what you eat and when pain occurs
  • **Try an elimination diet** — remove dairy, gluten, and high-FODMAP foods for 2 weeks and reintroduce one at a time
  • **Increase fibre gradually** — 30–35g per day from diverse sources supports gut health [8]
  • **Manage stress** — mindfulness and breathing exercises reduce stress-related gut symptoms [9]
  • **Consider gut-supportive supplementation** — [Epismed I](/products/epismed-i-immunity) contains polyphenol-rich botanical ingredients developed with reference to research on gut microbiome balance

For bad stomach cramping and diarrhoea

This combination most commonly indicates gastroenteritis or food sensitivity. Stay hydrated (water, electrolyte solutions), eat bland foods (rice, toast, bananas), and rest. If diarrhoea lasts more than 3 days or contains blood, see your GP [5].

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Frequently asked questions

What causes a bad stomach ache?

The most common causes are food intolerances, gastroenteritis, IBS, menstrual pain (for women), stress, and gut microbiome imbalance. Less commonly, it can indicate appendicitis, gallstones, or other conditions requiring medical treatment [1][6].

What causes a bad stomach ache after eating?

The most common triggers are food intolerances (dairy, gluten, FODMAPs), gallbladder issues (especially after fatty meals), gastritis, overeating, and acid reflux. If it happens regularly for more than 2 weeks, see your GP [1][4].

What helps a bad stomach ache?

Immediate relief: warm fluids, a hot water bottle, rest, and gentle movement. For recurring pain: a food diary, elimination diet, increased fibre intake, stress management, and gut-supportive nutrition [8][9][10].

When should I worry about a bad stomach ache?

Seek urgent medical attention if pain is sudden and severe, accompanied by blood, fever, rigid abdomen, breathing difficulty, or occurs during pregnancy. For recurring pain lasting more than 2 weeks, see your GP [1].

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References

[1] National Institute for Health and Care Excellence (NICE). "Abdominal pain: assessment and management." *NICE Clinical Knowledge Summaries*. 2023.

[2] Lacy BE, Weiser KT, Kennedy AT. "Functional dyspepsia and food intolerance." *Gastroenterology*. 2018;154(6):1557–1567.

[3] Storhaug CL, Fosse SK, Fadnes LT. "Country, regional, and global estimates for lactose malabsorption in adults." *The Lancet Gastroenterology*. 2017;2(10):738–746. doi:10.1016/S2468-1253(17)30154-1

[4] Staudacher HM, Whelan K. "The low FODMAP diet: recent advances." *Gastroenterology*. 2017;152(2):301–306.

[5] Elliott EJ. "Acute gastroenteritis in children." *BMJ Clinical Evidence*. 2007;2007:0314.

[6] Ford AC, Lacy BE, Talley NJ. "Irritable bowel syndrome." *The Lancet*. 2020;391(10123):839–850.

[7] Armour M, Parry K, Al-Dabbous M, et al. "Menstrual pain prevalence and impact." *BMJ Open*. 2019;9(2):e026186. doi:10.1136/bmjopen-2018-026186

[8] Hjørne AP, Moden IM, Hjorth MF, et al. "Dietary fibre and gut microbiome recovery." *Gut*. 2018;67(10):1741–1750.

[9] Vanuytsel T, van Wanrooy S, Vanheel H, et al. "Psychological stress and gut function." *Neurogastroenterology and Motility*. 2018;30(3):e13270.

[10] Nasef NA, Mehta S, Morgan B, et al. "Peppermint oil for IBS: a systematic review." *BMC Complementary Medicine and Therapies*. 2019;19(1):21. doi:10.1186/s12906-019-2426-y

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*This article is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. If you are experiencing severe or persistent abdominal pain, please consult your GP or call 111. Epismed I is a food supplement designed to support general gut wellbeing, not a medical treatment.*

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