Brief, factual descriptions of conditions that may be discussed during a gastroenterology consultation.
Hong Kong gastroenterology and hepatology information from Dr Paul Ng. Consultations in Central and Tsim Sha Tsui are by appointment; assessment and care are individual.
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Gut–brain & bowel function
Disorders of gut–brain interaction (DGBI)
DGBI is a group of conditions in which communication between the digestive tract and nervous system is altered. Gut movement, sensitivity to stretching, and the way signals are processed can interact, producing pain, bloating or bowel changes even when routine tests do not show structural disease. These are genuine disorders, not imagined symptoms; IBS and functional dyspepsia are examples.
Gut–brain signalling is bidirectional: digestion sends signals to the nervous system, and nervous-system activity can influence gut movement and sensitivity. Sleep, stress and prior illness may affect symptoms without making them unreal or implying that a person is at fault. Normal routine investigations can be reassuring when they fit the clinical picture, but they do not mean that symptoms should be dismissed. Because this umbrella includes different conditions, a useful plan starts by identifying the dominant problem and checking for changes or warning signs that would call for reassessment. Some people benefit from learning how symptom patterns relate to meals, sleep or daily routines, while others need a different focus; there is no one approach for every DGBI. Review over time can help determine whether the working explanation remains appropriate. A symptom timeline can help show whether pain, bowel changes or fullness fluctuate, and whether daily function is affected. New bleeding, progressive difficulty swallowing, fever or unintended weight loss should prompt assessment for causes outside a gut–brain disorder.
For discussion in consultation
Assessment starts with the particular symptom pattern and its effect on life, while checking for features or history that could point to another illness. There is no single test for the whole DGBI group. Explanations and care are matched to the specific condition and may involve more than one approach, with review if symptoms change.
IBS is a recurring pattern of abdominal pain associated with bowel movements or a change in stool frequency or form. Some people mainly have diarrhoea, others constipation, and some alternate between the two; urgency, bloating and a sense of incomplete emptying can also occur. IBS is a gut–brain interaction disorder and is distinct from inflammatory bowel disease, although symptoms may overlap.
People with IBS can have different symptom patterns over time, and stool form may be more informative than frequency alone. Meals, infections, stress and changes in routine can coincide with flares, but triggers vary and are not always identifiable. IBS does not cause the tissue damage or inflammation characteristic of inflammatory bowel disease and does not itself mean cancer is present. Nonetheless, rectal bleeding, persistent fever, anaemia, night-time symptoms or unintentional weight loss merit assessment; a previous IBS diagnosis should not be used to explain away a new change. A symptom diary can help describe pain, stool pattern and possible associations without requiring a person to avoid foods unnecessarily. The clinical review can then focus on the most troublesome symptoms and whether testing is justified by the history. A careful history may help avoid unnecessary broad testing while still identifying a reason for targeted tests. New symptoms, a substantial change from the usual pattern, or a relevant family history should be reviewed rather than assumed to be part of IBS.
For discussion in consultation
A diagnosis is based on a characteristic history and appropriate clinical assessment, not simply on a normal scan. The duration and pattern of symptoms, family history, age and warning features such as bleeding, anaemia, fever or unintentional weight loss help determine whether targeted tests are appropriate. New, persistent or substantially changing symptoms still deserve review.
Functional constipation is ongoing difficulty with bowel movements without an identified structural explanation. Stools may be hard or lumpy, occur less often, require straining, or leave a feeling that the bowel has not emptied. Bloating and abdominal discomfort may accompany it. Frequency alone does not define constipation, and symptoms can overlap with other bowel disorders.
A bowel diary can help describe stool form, frequency, straining and the feeling after a bowel movement. Causes may include a change in routine, low fibre intake, medicines or other health conditions; increasing fibre is not suitable for every person or every cause and should be discussed if symptoms are significant. When pelvic-floor coordination is a problem, simply trying to pass stool more often may not address it. New severe pain, vomiting, inability to pass gas, blood in stool or a sudden persistent change should be medically assessed. The review may also ask about the time spent on the toilet, posture and whether pressure or manual assistance is needed, since these details can point to an evacuation problem. Persistent symptoms despite initial measures warrant reassessment rather than repeated unsupervised changes. A clinician may review medicines such as some pain medicines or iron, which can contribute, and ask whether stool feels difficult to pass despite being soft. These details help distinguish slow transit from an evacuation or pelvic-floor coordination problem.
For discussion in consultation
Assessment reviews the timeline, stool pattern, diet and fluid intake, activity, illnesses and medicines that may contribute. Persistent straining or incomplete emptying can sometimes reflect difficulty coordinating pelvic-floor muscles rather than stool consistency alone. The likely cause, associated symptoms and prior measures guide discussion of suitable options and whether further evaluation is needed.
Functional dyspepsia is a disorder of gut–brain interaction that can cause upper abdominal pain or burning, feeling full unusually early, or uncomfortable fullness after meals, without another disease adequately explaining the symptoms after appropriate assessment.
Symptoms are real and do not mean that an ulcer, cancer or delayed stomach emptying is present. Functional dyspepsia is not simply another name for gastritis or gastroparesis, although conditions may overlap. Assessment considers the symptom pattern, medicines, H. pylori and other possible causes. Endoscopy is not automatic for every patient; age, family history, alarm features and local risk influence the decision. Care may include dietary adjustments, H. pylori treatment when indicated, acid suppression or other individually selected treatments.
For discussion in consultation
Discuss persistent or recurrent symptoms rather than repeatedly self-treating. Progressive swallowing difficulty, unexplained weight loss or persistent vomiting need prompt review. Vomiting blood or black, tarry stools may require emergency assessment.
Related procedure information
These links are general information, not a recommendation for an examination or treatment.
These summaries are for general information only. They cannot establish a diagnosis or determine whether you need tests, surveillance or treatment. Your own results, risks and options must be reviewed in an actual consultation with a qualified clinician. Do not start, stop or change treatment based on this page.
References are provided for background reading; they do not replace a consultation.
Questions about a finding on your scan, blood test or endoscopy report? Discuss the full report and your history in a consultation.
About this information
This is general educational information, not a diagnosis, a personalised recommendation or consent for a procedure. Whether to investigate or treat, the alternatives (including no procedure), benefits and risks require individual clinical assessment and discussion.