Gastroenterology is the branch of medicine that focuses on the digestive system and its disorders. This includes the oesophagus, stomach, intestines (small and large), liver, pancreas, gallbladder, rectum, how food is moving through the stomach and intestines and how nutrients are digested and absorbed. There are many medical conditions that affect the gastrointestinal or digestive system, some of which are treatable, others which can be managed through medication and lifestyle.
Abdominal pain refers to any discomfort or pain that occurs between the chest and the pelvis, commonly associated with the gastrointestinal (GI) system but can also involve other systems like the urinary or reproductive systems. Gastroenterology focuses on identifying, diagnosing, and treating abdominal pain when it’s related to issues with the digestive organs, like the stomach, intestines, liver, and pancreas.
Abdominal pain is often one of the primary symptoms that lead individuals to see a gastroenterologist. Gastrointestinal issues like acid reflux, ulcers, or inflammatory bowel disease (IBD) can result in chronic or acute abdominal discomfort. The location, type, and severity of the pain can help the doctor determine what part of the digestive system is involved.
Causes of Abdominal Pain Related to Gastroenterology:
Acid reflux, also known as gastroesophageal reflux disease (GERD) when it becomes chronic, is a condition where stomach acid or bile irritates the food pipe (oesophagus). It happens when the lower oesophageal sphincter (LES), a valve between the stomach and oesophagus, becomes weak or relaxes inappropriately, allowing stomach contents to flow back up.
Causes of Acid Reflux:
Weak or Relaxed LES: The LES normally keeps stomach acid in the stomach, but if it weakens or relaxes at the wrong times, acid can flow back into the oesophagus.
Hiatal Hernia: A condition where part of the stomach pushes up through the diaphragm into the chest, which can make it easier for acid to reflux into the oesophagus.
Obesity: Excess weight, especially around the abdomen, can put pressure on the stomach, forcing acid up into the oesophagus.
Pregnancy: Hormonal changes and the growing uterus can put pressure on the stomach, leading to acid reflux.
Dietary Factors:
Smoking: Smoking can weaken the LES and reduce saliva production, which helps neutralize acid.
Certain Medications: Some medications (e.g., aspirin, ibuprofen, blood pressure meds, sedatives) can relax the LES and increase acid reflux risk.
Delayed Stomach Emptying: If the stomach takes too long to empty its contents, it can contribute to reflux.
Symptoms of Acid Reflux:
Dysphagia is the medical term for difficulty swallowing. It can make it hard to swallow solid foods, liquids, or even saliva. Dysphagia may occur when there are problems in the mouth, throat (oropharyngeal), or oesophagus (the tube connecting the throat to the stomach). It can be a temporary issue or a more chronic condition.
Causes of Dysphagia:
1. Oropharyngeal Dysphagia (problem in the mouth or throat)
This type of dysphagia occurs when the muscles or nerves in the mouth or throat are impaired, making it difficult to move food from the mouth into the esophagus.
Neurological conditions:
Head or neck cancers: Tumors or cancer treatments (radiation, surgery) can impact swallowing muscles or the esophagus.
Throat infections or inflammation: Infections like tonsillitis or pharyngitis can temporarily cause difficulty swallowing.
2. Oesophageal Dysphagia (problem in the oesophagus)
This occurs when there’s an issue in the oesophagus that affects the passage of food to the stomach.
3. Other Causes:
Irritable Bowel Syndrome (IBS) is a chronic gastrointestinal disorder that affects the large intestine (colon). It is characterized by symptoms such as abdominal pain, bloating, and changes in bowel habits (diarrhea, constipation, or alternating between the two). IBS is a functional GI disorder, meaning there are no visible signs of disease or structural problems in the digestive tract, but the digestive system isn’t functioning properly.
Symptoms of IBS:
Symptoms can range from mild to severe, and they often flare up in response to certain triggers, such as food, stress, or hormonal changes.
Causes of IBS:
The exact cause of IBS is not fully understood, but several factors are thought to contribute to its development. These include:
1. Abnormal Muscle Contractions in the Intestines:
The muscles in the walls of the intestines contract to move food through the digestive tract. In IBS, these muscles may contract too strongly or too weakly, leading to symptoms like cramps, bloating, or changes in bowel movements.
2. Gut-Brain Interaction:
The gut and the brain are closely connected, and changes in how they communicate may play a role in IBS. Stress, anxiety, or emotional distress can trigger IBS symptoms, suggesting that the brain-gut connection is important.
3. Inflammation:
Some people with IBS may have low-grade inflammation in the gut, which can contribute to symptoms like pain and discomfort.
Infections or Food Sensitivities:
5. Altered Gut Microbiome:
The bacteria in your gut (known as the microbiome) play an important role in digestion and overall gut health. An imbalance in gut bacteria, known as dysbiosis, may contribute to IBS.
6. Genetics:
There may be a genetic predisposition to IBS, as it can run in families. However, specific genes related to IBS are still being researched.
7. Hormonal Changes:
IBS is more common in women, and symptoms often worsen during menstruation or pregnancy, suggesting that hormonal fluctuations may play a
role.
8. Stress and Mental Health:
Stress and anxiety are known triggers for IBS symptoms. Many people with IBS experience flare-ups after stressful events or periods of high emotional stress.
Fatty liver (also known as hepatic steatosis) is a condition where excess fat builds up in the liver cells. Normally, the liver processes and removes fat, but in cases of fatty liver, the liver becomes overwhelmed, leading to fat accumulation. The condition can be benign, but if it progresses, it may lead to liver damage, inflammation, and more serious conditions like cirrhosis or liver failure.
There are two main types of fatty liver disease:
Non-Alcoholic Fatty Liver Disease (NAFLD)
Alcoholic Fatty Liver Disease (AFLD)
Causes of Fatty Liver:
1. Non-Alcoholic Fatty Liver Disease (NAFLD):
This is the most common form and is not related to alcohol consumption. It’s primarily linked to metabolic conditions such as:
2. Alcoholic Fatty Liver Disease (AFLD):
3. Other Causes:
Symptoms of Fatty Liver:
In the early stages, fatty liver often doesn’t cause any symptoms. As the condition progresses, symptoms may develop, including:
Diagnosis of Fatty Liver:
Fatty liver is usually diagnosed through a combination of medical history, physical exams, blood tests, and imaging studies such as:
Dyspepsia, commonly known as indigestion, refers to a group of symptoms that cause discomfort or pain in the upper abdomen. It is often related to problems with the stomach or the upper part of the small intestine, where food is digested. People with dyspepsia may experience symptoms such as bloating, nausea, burping, and a feeling of fullness after eating.
Symptoms of Dyspepsia:
Causes of Dyspepsia:
Dyspepsia can be caused by a wide range of conditions, and in some cases, no specific cause is found (this is called functional dyspepsia). Here are the most common causes:
1. Gastroesophageal Reflux Disease (GERD):
2. Gastritis:
3. Peptic Ulcers:
4. Functional Dyspepsia:
5. Helicobacter Pylori Infection:
6. Medications:
7. Overeating or Eating Too Quickly:
8. Food Intolerances or Sensitivities:
9. Stress and Anxiety:
10. Other Gastrointestinal Disorders:
11. Endocrine Disorders:
12. Cancer:
Diagnosis of Dyspepsia:
To determine the cause of dyspepsia, your healthcare provider may recommend several tests, including:
You can be referred to our service by your GP.
Yes. For many NHS services, you have the right to choose where you are treated. You can discuss this with your GP at the time of referral.
This service is for adults aged 18 and over only.
If you require care for a child or young person, please contact your GP for advice on appropriate services.
We treat a range of digestive system conditions, including:
In some cases, you may be asked to complete tests (such as blood or stool tests) before your appointment. If required, we will provide clear instructions.
Generally, no special preparation is needed unless we advise otherwise. If preparation is required, you will be informed in advance.
Please bring:
Our patient information leaflet explains what happens during a gastroenterology appointment, how to prepare, what the procedure involves, and what to expect afterwards.
Appointments typically last between 15-20 minutes, depending on your needs.
Yes. If you need to rearrange your appointment, please contact the appointments team as soon as possible. We require at least 24 hours’ notice for appointment changes or cancellations wherever possible. Failure to attend appointments, or repeated late cancellations with less than 24 hours’ notice, may result in you being discharged back to your GP.
You may be referred for tests such as blood tests, stool tests, imaging scans, or endoscopic procedures.
These are procedures used to examine the digestive tract using a thin, flexible tube with a camera. An endoscopy looks at the upper digestive system, while a colonoscopy examines the large bowel.
Some tests may be carried out at a different clinic or hospital where we have established pathways. You will be provided with full details of where to go and how to prepare.
Once your test results are available, they will be reviewed by our clinical team. We will then follow up with you to discuss the results and any next steps in your care.
Where appropriate, you may be given advice, a management plan, or referred for further tests during your first appointment.
This depends on your condition and treatment plan. Your clinician will advise you.
If your condition requires specialist or hospital-based care, we will arrange a referral.
If treatment is needed, we will send instructions to your GP, who can issue a prescription if appropriate. We may also advise on over-the-counter treatments where relevant.
Yes. Your GP will usually continue your care following our assessment, based on the instructions provided by our clinicians.
If your symptoms do not improve or worsen, please contact your GP or our service for further advice.
If your symptoms worsen, please contact your GP. For urgent concerns, seek immediate medical advice.
Seek urgent medical attention if you experience:
You can contact our service for advice, or speak to your GP if you have ongoing concerns.
I am a Consultant Gastroenterologist and Specialist Endoscopist. I have a patient centered approach and strive to provide high quality, safe, efficient and individualised care to all my patients.
Dr. Rajaratnam Rameshshankar is a Consultant Gastroenterologist and Specialist Endoscopist at Hillingdon Hospitals NHS Foundation Trust in West London. He completed his specialist training in Gastroenterology and Internal Medicine in Northwest London and earned a Doctorate in Medicine from Imperial College London in 2020.
He trained at the Wolfson Institute, St. Mark’s Hospital, gaining expertise in advanced endoscopic techniques, and completed a fellowship in ERCP at Hammersmith Hospital. Appointed as a full-time NHS Consultant in 2018, he leads advanced endoscopy services including ERCP and complex colonoscopy. He is an Honorary Senior Lecturer at Imperial College London.
Dr. Shameer Shah graduated from the University of Manchester in 2001 and initially trained in Gastroenterology, gaining expertise in digestive and liver conditions before completing GP training in 2008. He continues to focus on gut health within general practice, supporting patients with conditions such as inflammatory bowel disease and coeliac disease, while also holding diplomas in cardiology and diabetes.
A dedicated educator, he mentors students, doctors and GP registrars, and serves as a GP appraiser, and is also a GP Principal in Harrow. Dr Shah works as a GPwER within Harrow Health’s gastroenterology service.
Dr Uma Selvarajah is a Consultant Gastroenterologist based in Northwest London, with specialist expertise in inflammatory bowel disease, upper gastrointestinal disorders, and neurogastroenterology. Trained to a high standard locally, she combines her clinical acumen with a deeply patient-centred philosophy of care.
Dr Selvarajah is committed to delivering treatment that is both compassionate and evidence-based, ensuring her patients feel heard, supported and involved throughout their care journey. Whether managing chronic conditions or diagnosing complex gastrointestinal issues, her goal is always the same: to achieve optimal outcomes while upholding dignity, understanding and respect.
Dr Alexandros Toskas is a Consultant Gastroenterologist at St Mark’s Hospital with subspecialist expertise in Inflammatory Bowel Disease (IBD). He completed his PhD in Gastroenterology at the Aristotle University of Thessaloniki, where his research focused on cytokine expression in IBD mucosa, and has since published extensively on IBD pathogenesis, biologic therapies, and infliximab optimisation. He undertook specialist training in the UK, followed by an advanced endoscopy fellowship at St Mark’s Hospital.
He is JAG-accredited in colonoscopy and upper GI endoscopy, with additional expertise in video capsule and interventional endoscopy. Dr Toskas has presented at major international meetings including ECCO, ESGE, and UEG, and contributed to multicentre studies on perianal Crohn’s disease and novel IBD therapeutics. He is a Fellow of the European Board of Gastroenterology and Hepatology (FEBGH). At St Mark’s, he has led quality improvement initiatives, including the development of local guidelines for acute severe colitis and inpatient IBD care pathways. In parallel with his clinical and research commitments, he serves as Gastroenterology Module Lead for Brunel University undergraduate students, with an active role in teaching, training, and mentoring. His academic and clinical work reflect a strong commitment to advancing personalised IBD care through translational research, and multidisciplinary collaboration.
Expert care for a wide range of women’s health concerns, from routine assessments to complex gynaecological conditions.
