Abdominal pain is a very common presenting complaint in both primary and secondary care settings, and with thousands of potential diagnoses it can present a very challenging diagnostic process.
The aim of this article is to give an overview of the wide variety of potential diagnoses, highlight important aspects of assessing and managing patients who present with both acute and chronic abdominal pain. Some typical presentations of common causes of abdominal pain are included - more information on the specific pathologies is available in the relevant articles throughout the website.
Types and Causes of Abdominal Pain
Abdominal pain can occur either as an acute episode or be an ongoing, chronic symptom. The approach to assessing and investigating pain in the abdomen differs depending on whether it is acute or chronic situation so they will be discussed separately later in the article.
The nature of abdominal pain can act as a useful starting point for narrowing down the differentials and directing further questions and investigations. The following specific 'types' of pain have been described;
1. Colicky pain: Pain that comes and goes in waves - suggests a blockage in a hollow organ (e.g. renal stone)
2. Aching pain: pain from an inflamed organ (e.g appendicitis)
3. Peritonitic pain - Severe pain worsening on movement/with coughing - indicates free fluid in the peritoneum causing irritation (e.g. due to bowel perforation)
These different types of pain in the abdomen are often caused by pathology of the underlying structures - with so many systems having organs located in the abdomen there is a lot to consider. The gastrointestinal, renal, urinary, and reproductive systems are all potential suspects.
However pain can also be referred to the abdomen from the thorax (e.g. MI and lower lobe pneumonia) or caused by vascular pathology (e.g. dissecting/ruptured AAA or mesenteric artery ischaemia). Although these are rarer causes, they can be life-threatening so it is vital that these possible causes are considered.
It can be useful to divide the abdomen in to nine sections and consider what problems might cause pain in each area. There is a very useful diagram in the 'Acute Abdomen' article by Philip Ireland in the General Surgery section of notes.
Assessing Abdominal Pain - SOCRATES
Acute Abdominal Pain
Patients who suffer with acute abdominal pain normally present to A&E, however some may present to their GP and also patients who are already hospitalised (especially surgical patients) may suddenly develop abdominal pain.
It is important to feel confident in recognising emergency, life-threatening presentations and getting senior colleagues and/or the relevant specialist teams involved at an early stage.
Assessment of acute abdominal pain
FIRST THINGS FIRST
- As always when assessing a patient with an acute symptom begin with the basic check - assess Airway, Breathing and Circulation and look at most recent observations to ensure patient is stable before proceeding
- If not, attempt to stabilise the patient and have a low threshold for calling for senior help if having difficulty
- Once the patient is stable, begin a focussed history asking about the pain using SOCRATES pain assessment tool
- Enquire about personal and family history of abdominal pain, including specific pathologies such as Inflammatory bowel disease (IBD)/peptic ulcer disease (PUD)
- Ask the patient about their general health and any medications they are taking - some medicines may be indicated as exacerbating factors in specific conditions and would thus need to be discontinued (e.g. NSAIDs in PUD)
- If the patient has recently had abdominal surgery it may be that the current pain is due to a complication such as perforation, obstruction or collection so remember to ask specifically about this and review the patient's notes
- Carry out a focussed examination, bearing in mind what structures underlie certain areas of the abdomen
- An acute abdomen presents with rigidity, guarding and rebound tenderness - this is a surgical emergency and requires immediate investigation and management
- Further examination will be dictated by the findings in the history and abdominal examination - for example; PR exam, examination of the external genitalia, assessment of the hernial orifices.
- Immediate investigations may include an ECG to rule out a cardiac cause, erect CXR (?perforation, in which case free air would be seen under the diaphragm) and AXR (?intestinal obstruction)
- Baseline bloods should be taken - FBC, U&E, LFT, glucose, CRP, clotting - include amylase (marker of pancreatitis), - group and save in preparation for potential surgery and in case of suspected bleeding - always take a bHCG in women of childbearing age as ectopic pregnancy could be the cause
- In the case of an ACUTE ABDOMEN, the on call surgical team should be contacted immediately, and the patient should be made nil by mouth in case they require surgery
- Further investigations will be guided by history and examination findings - they may include ultrasound in cases where hepatobiliary/gynaecological cause is suspected, KUB/IVU if the problem seems likely to be renal or endoscopy if the GI tract is implicated
- Referral to the appropriate specialist team may be necessary once the likely underlying cause of the pain has been decided
Chronic Abdominal Pain
Abdominal pain that has been ongoing - either continuously or intermittently - for over 6 months is termed 'chronic'.
Chronic abdominal pain can be difficult to diagnose as it can be very non-specific and pain is also a particularly subjective experience so patients who have the same underlying pathology may present quite differently.
A thorough consultation is needed to ensure all the relevant information regarding the symptom is gleaned and to direct appropriate investigations to get to the correct diagnosis.
- Information about the pain should be obtained using SOCRATES which will help to exclude/include certain pathologies and tailor investigations
- The associated symptoms can be particularly helpful, giving an indication of which system the problem might be originating from and narrow the differentials (for example constipation/diarrhoea would indicate a GI pathology, whereas dysuria would suggest the urinary tract to be the origin of the patient's pain)
- Asking about the patient's general health and any medications taken may highlight a likely cause for the presenting pain
- It is also important to consider lifestyle factors, including diet, smoking - which can be an exacerbating factor in Crohn's disease but may actually be preventative in ulcerative colitis - and alcohol which is associated with pancreatitis and liver disease.
- A family history of any specific pathology may also flag up a potential diagnosis
- A full abdominal examination should be performed, again keeping in mind the structures that underlie specific areas of the abdomen and typical patterns of pain
- A brief assessment of the patient's cardiovascular and respiratory systems may also be pertinent
- It might be necessary to conclude by also performing examination of the external genitalia, rectal examination, vaginal examination
- the history and examination may have revealed the likely cause of the pain and if this is something that can be easily treated the appropriate treatement should be initiated
- Treatment may include lifestlye changes like dietary modifications, stopping smoking/reducing alcohol intake. Simple pharmacological treatments may be indicated, for example antacids/PPI for suspected GORD, or a course of antibiotics may be necessary if suspicious of UTI.
- However, in many cases additional investigations will be needed to confirm the diagnosis and plan for treatment: these investigations may include blood work-up, scans, endoscopy, and the patient may require referral to specialists for further management
'Functional' Abdominal pain
No organic cause is found in a significant proportion of patients suffering from abdominal pain - this is termed 'non-organic' or 'functional' pain.
- Remember that this is a diagnosis of exclusion - the pain must be investigated to confidently rule out other potential causes. However it is important to be careful not to over investigate when it has become clear that the most likely diagnosis is a functional pain as this can cause unnecessary stress for the patient and is also wasteful of resources
- Explaining to the patient that there is no organic cause for the pain should be undertaken sensitively as it can be very difficult to come to terms with experiencing pain that cannot be adequately explained
- Functional abdominal pain often cannot be cured but can be managed if adequately monitored by the patient with the support of his/her healthcare team and the symptoms treated appropriately (using laxatives/bulking agents/anti-spasmodics)
- Abdominal Pain is a very common presentation in both primary and secondary care
- There are a great deal of causes of abdominal pain to consider when a patient presents with this symptom, ranging from life-threatening/emergency conditions to functional disorders
- Assessing acute pain, as with any acute symptom must begin with an ABCDE assessment of the patient and rapid stabilisation as needed. If a patient is generally unwell there should be a low threshold for contacting seniors for assistance. Also an 'acute abdomen' requires immediate assessment by surgeons
- Full exploration of a patient's pain symptom is needed - using SOCRATES to determine specifics about the pain, and discussing the patient's general health, lifestyle and family history can help to narrow the exhaustive list of diagnoses to a single diagnosis/manageable set of differentials which can be treated/investigated further if necessary
References and suggestions for further reading
Best Practice, Assessment of Chronic Abdominal Pain: http://bestpractice.bmj.com/best-practice/monograph/767.html
Crash Course Gastrointestinal System, second edition. Long, Cheshire. Elsevier Health Sciences, 2002.
Oxford Handbook for the Foundation Programme, second edition. Chapter 9: Clinical Presentations, Abdominal Pain. Hurley, Dawson, Sanders, Eccles. Oxford University Press, 2008.
www.uptodate.com specifically the following pages; 'History and physical examination in adults with abdominal pain', 'Differential diagnosis of abdominal pain in adults' and 'Diagnostic approach to abdominal pain in adults'
Zirva Ahmad 'Gastroduodenal Ulcers' Fastbleep: http://www.fastbleep.com/medical-notes/gi-and-renal/11/19/96