Quick answer: Symptoms of inflammation of the small intestine include abdominal pain, diarrhoea, nausea, loss of appetite, fatigue and weight loss. The acute form may resolve within a few days, but the chronic form — for example, in cases of Crohn’s disease or coeliac disease — requires more thorough investigation. If symptoms persist, you should consult a gastroenterologist.
The symptoms of inflammation of the small intestine are often mistaken for a simple upset stomach. A few days of feeling unwell, bloating, and poor digestion — and you might think you’ve just eaten something that didn’t agree with you. However, this misdiagnosis can be dangerous if there is a more serious underlying condition.
The small intestine — also known as the enteritis — is one of the most important sections of the digestive tract. It is situated between the stomach and the large intestine, and its primary function is the absorption of nutrients. If this section becomes inflamed, not only is digestion disrupted, but the body’s proper nutrition may also be compromised.
In this article, we explain in detail the symptoms of inflammation of the small intestine, what might be causing it, how it is diagnosed, and when you should consult a specialist. The experienced specialists at the Endomedix Gastroenterology Clinic will help you to identify the cause of your symptoms as soon as possible, based on the appropriate tests.
What is the role of the small intestine in the body?
The small intestine is a section of the intestine, 4–6 metres long, situated between the stomach and the large intestine. It consists of three parts: the duodenum, the jejunum and the ileum (ileum). Its wall is covered with tiny, finger-like projections — known as villi — which dramatically increase the surface area available for absorption.
Food passes from the stomach into the small intestine in a semi-digested state, where it is broken down further with the help of pancreatic enzymes and bile acids. The nutrients released — carbohydrates, proteins, fats, vitamins and minerals — are absorbed by the villi and transported into the bloodstream.
If the small intestine becomes inflamed, this delicate and complex system is damaged. The intestinal villi become shorter or disappear, absorption is impaired, and the body may gradually develop a nutrient deficiency — even if the patient eats regularly.
What are the symptoms of inflammation of the small intestine?
The symptoms of inflammation of the small intestine can vary considerably, depending on the extent, cause and severity of the inflammation. It is worth dividing them into two groups: gastrointestinal symptoms and general physical symptoms.
Digestive and abdominal complaints
- Abdominal pain: It most commonly occurs around the navel or in the lower right abdomen, and may feel cramp-like, colicky or like a dull pressure. It may become more intense after a meal.
- Diarrhoea: It is one of the most characteristic symptoms of inflammation of the small intestine. It may be watery, foul-smelling, or have a greasy appearance (steatorrhoea); it is rarely bloody.
- Nausea and vomiting: It mainly occurs in cases of acute, infectious aetiology, but may also occur in cases of chronic inflammation.
- Bloating and flatulence: It is the result of the proliferation of gut bacteria and fermentation processes.
- Loss of appetite: The inflammatory process generally reduces the appetite, which further impairs nutrient intake.
- Changes in bowel habits: Alternating diarrhoea and constipation, or an unusual volume or consistency of stools.
General physical symptoms
- Weight loss: Due to malabsorption, the body does not receive enough calories, and body weight decreases involuntarily.
- Fatigue and weakness: It may be caused by anaemia resulting from iron deficiency, vitamin B12 deficiency or other nutrient deficiencies.
- Fever: In the event of an infection or an active inflammatory process (for example, during a flare-up of Crohn’s disease), a temperature above 37.8 °C may occur.
- Oedema: In cases of severe protein deficiency, fluid may accumulate in the lower limbs.
- Skin, nervous system and skeletal symptoms: Deficiencies in vitamins K, D and B can lead to haemorrhagic disorders, neuropathy and bone pain.
When should you see a doctor straight away?
Certain symptoms require urgent medical attention. Please consult a healthcare professional immediately if:
- bloody or black stools appear,
- severe, cramp-like abdominal pain occurs and does not subside,
- the diarrhoea lasts for more than 3 days or is accompanied by a high fever,
- there are signs of severe dehydration (thirst, low urine output, dizziness),
- Unintentional weight loss occurs within a few weeks.
What causes inflammation of the small intestine?
There are many different causes of inflammation of the small intestine — ranging from a temporary stomach infection to more serious chronic conditions.
Infections: bacteria, viruses, parasites
Acute enteritis is most often caused by an infection. The most common pathogens are:
- Bacteria: Salmonella, Escherichia coli (ETEC, EPEC), Campylobacter jejuni, Shigella, Yersinia enterocolitica
- Viruses: Rotavirus (particularly common in children), Norovirus (Norwalk agent)
- Parasites: Giardia lamblia, Cryptosporidium
These pathogens enter the body via contaminated food, water or poor hygiene. So-called „traveller’s diarrhoea” is also typically the result of such an infection. The symptoms usually subside within a few days, but in the case of a bacterial infection, treatment with antibiotics may also be necessary.
Autoimmune diseases and chronic conditions
Chronic inflammation of the small intestine is most often caused by autoimmune processes:
- Crohn's disease: It is the most common chronic inflammatory disease of the small intestine. It mainly affects the terminal ileum, but can occur in any part of the gastrointestinal tract. It is characterised by transmural inflammation (affecting the entire thickness of the intestinal wall), ulcers and strictures.
- Coeliac disease (celiac disease): Consumption of gluten triggers an autoimmune reaction which damages the villi of the small intestine. This results in severe malabsorption.
- Eosinophilic enteritis: An inflammatory condition with an allergic or immunological aetiology, which must be distinguished from coeliac disease.
- SIBO (small intestinal bacterial overgrowth): An abnormal amount of bacteria colonising the small intestine causes bloating, abdominal discomfort and diarrhoea.
Other contributing factors
- Medicines: NSAIDs (non-steroidal anti-inflammatory drugs) and antibiotics can irritate the intestinal lining, causing ulcers and enteropathy.
- Radiotherapy: Radiation enteritis may develop as a side effect of cancer treatment, leading to chronic malabsorption and bowel failure.
- Ischaemic bowel disease: A disruption to the blood supply to the small intestine causes inflammation and tissue damage — particularly in elderly patients with circulatory problems.
How is inflammation of the small intestine diagnosed?
The symptoms of inflammation of the small intestine are not, on their own, sufficient to make an accurate diagnosis. Identifying the underlying cause requires a detailed examination.
Medical history and physical examination: The doctor will ask detailed questions about the symptoms, their duration, eating habits, medication and any previous illnesses. By palpating the abdomen, the doctor can determine the location and nature of the pain.
Laboratory tests: Blood tests can detect inflammatory markers (CRP, erythrocyte sedimentation rate), anaemia, and vitamin and mineral deficiencies. Stool tests can identify infections and occult bleeding.
Imaging studies: An abdominal ultrasound, CT scan or MRI can help to identify thickening of the bowel wall, strictures, abscesses and other complications.
Endoscopic examinations: Capsule endoscopy can be used to directly visualise the inside of the small intestine — a swallowable, camera-sized capsule that travels through the intestinal tract and captures images. A tissue sample (biopsy) may also be required to determine the type of inflammation.
Special tests: SIBO and intolerance can be diagnosed using breath tests (lactulose, lactose H₂ test). If gluten sensitivity is suspected, serological and histological tests are required.
Treatment options for inflammation of the small intestine
Treatment always depends on the underlying condition and the severity of the symptoms — there is no single solution that works in every case.
Medication
- In the event of an infection: If the cause is bacterial, antibiotics are required; in the case of a viral infection, treatment is symptomatic (rehydration, rest).
- Anti-inflammatory drugs: In cases of Crohn’s disease or colitis, corticosteroids (e.g. prednisolone) and 5-ASA derivatives (e.g. mesalazine) reduce inflammatory activity.
- Immunomodulators and biological agents: In cases of severe autoimmune conditions, azathioprine, methotrexate or anti-TNF-α biologics (e.g. infliximab, adalimumab) may be used.
- Probiotics: They are recommended for restoring the balance of the gut flora, particularly following a course of antibiotics.
Dietary and lifestyle changes
- People with coeliac disease need to follow a gluten-free diet for life.
- A low-FODMAP diet may help reduce gut irritation in cases of IBS and SIBO.
- In cases of persistent diarrhoea, it is particularly important to drink plenty of fluids (at least 2–3 litres a day) to restore electrolyte balance.
- Vitamin and mineral supplements can help to correct deficiencies caused by malabsorption (iron, vitamin B12, vitamin D, zinc, calcium).
Possible complications if inflammation of the small intestine is left untreated
The symptoms of untreated or inadequately treated inflammation of the small intestine gradually worsen and can lead to serious complications:
- Intestinal obstruction: Scarring and narrowing caused by chronic inflammation make it difficult for digested material to pass through the digestive tract.
- Intestinal perforation: In severe cases, the intestinal wall may rupture, leading to peritonitis and a life-threatening condition.
- Nutrient deficiency and malnutrition: A persistent malabsorption disorder leads to anaemia, osteoporosis and immunodeficiency.
- Abscesses and fistulas: Perianal abscesses and fistulas are particularly common in Crohn’s disease.
- Increased risk of cancer: Chronic inflammation may increase the long-term risk of certain cancers (e.g. small bowel lymphoma).
The role of Endomedix in the diagnosis of small bowel inflammation
Recognising the symptoms of small bowel inflammation and establishing an accurate diagnosis requires specialist knowledge in gastroenterology. The experienced specialists at the Endomedix Gastroenterology Clinic have been investigating and treating diseases of the small intestine and the digestive system for many years.
The small intestine cannot be examined using a standard gastroscopy or colonoscopy — this area requires specialised diagnostic tools and methods (e.g. capsule endoscopy, imaging tests, laboratory tests). Endomedix’s specialists draw up a personalised, evidence-based treatment plan based on all available test results.
If you are experiencing abdominal pain, persistent diarrhoea, unintentional weight loss or any other digestive problems, do not delay in getting checked out. Book an appointment at Endomedix for a consultation with a gastroenterologist, where a decision is made, based on a detailed medical history and physical examination, as to what further tests are required.
How to prevent inflammation of the small intestine
Infectious causes can largely be prevented through good hygiene:
- Regular and thorough handwashing, particularly before meals and in public places.
- Avoid eating raw meat, raw eggs and seafood from unreliable sources.
- When travelling, please exercise caution regarding the safety of places to eat and drinking water.
- Ensure good kitchen hygiene: regular disinfection and adherence to food storage rules.
In the case of chronic conditions (Crohn’s disease, coeliac disease), early detection is key, rather than prevention. The sooner a diagnosis is made, the more effective the treatment will be, and the lower the risk of serious complications.
If your symptoms keep coming back, don’t wait any longer. Book an appointment for a gastroenterology consultation at Endomedix, and receive a professional response to your concerns.
Frequently asked questions about inflammation of the small intestine
What are the symptoms of inflammation of the small intestine?
The most common symptoms of inflammation of the small intestine are: abdominal pain (mainly around the navel or in the lower right abdomen), diarrhoea, nausea, bloating, loss of appetite, fatigue, weight loss and, in some cases, fever. In more severe cases, bloody stools may also occur.
What is the difference between acute and chronic inflammation of the small intestine?
Acute enteritis is usually caused by an infection; it resolves within a few days and heals spontaneously. The chronic form — such as Crohn’s disease or coeliac disease — can persist for months or years, with recurring symptoms, and requires long-term treatment.
How is inflammation of the small intestine diagnosed?
To make a diagnosis, blood tests, stool tests, imaging tests (ultrasound, CT, MRI) and endoscopic procedures (such as capsule endoscopy) are required. The gastroenterologist makes an accurate diagnosis based on the symptoms and the results of these tests.
Which condition is the most common cause of chronic inflammation of the small intestine?
In adults, the most common cause is Crohn’s disease, which involves chronic inflammation of the small intestine — primarily the terminal ileum. Coeliac disease (gluten sensitivity) is also common; it causes autoimmune inflammation in the small intestine in response to the consumption of gluten.
When should you see a doctor if you suspect inflammation of the small intestine?
Seek medical advice immediately if your symptoms (diarrhoea, abdominal pain) persist for more than 3 days, if you notice blood in your stools, if you have a high fever, or if you show signs of severe dehydration. In the event of persistent or recurrent symptoms, a specialist gastroenterological examination is required.
Can inflammation of the small intestine be cured?
Infectious conditions usually result in a full recovery. Chronic autoimmune diseases (Crohn’s disease, coeliac disease) cannot be completely cured, but with appropriate treatment and lifestyle changes, patients can remain symptom-free in the long term, and their quality of life can be significantly improved.
