Chronic/Recurrent Abdominal Pain in Adults
This problem may present in any age group. In young to middle-aged adults, the cause is very likely to be benign, but this alters with age. Malignancy should always be suspected in the elderly even though other causes are still commoner. A precise diagnosis sometimes remains elusive.
Differential diagnosis
Common Diagnoses
- IBS
- Recurrent UTI
- Chronic Peptic Ulcer (PU)
- Constipation
- Diverticular Disease
Occasional Diagnoses
- Gallstones
- Hydronephrosis
- Post-Herpetic Neuralgia
- Inflammatory Bowel Disease
- Ureteric Colic
- Spinal Arthritis
- Coeliac Disease (Commoner than Traditionally Thought: 1 in 300 Adults)
Rare Diagnoses
- Mesenteric Artery Ischaemia (Abdominal Angina)
- Chronic Pancreatitis
- Subacute Obstruction (Adhesions, Malignancy and Diverticulitis)
- Functional (Psychogenic) Abdominal Pain
- Malignancy
- Metabolic Causes, e.g. Addison’s Disease, Porphyria, Lead Poisoning
Ready reckoner
Key distinguishing features of the most common diagnoses
| IBS | UTI | PU | Constipation | Diverticulitis | |
|---|---|---|---|---|---|
| High Abdominal Pain | Possible | No | Yes | Possible | Possible |
| Colicky | Yes | No | No | Yes | Yes |
| Weight Loss | No | Possible | Possible | No | No |
| Diarrhoea | Yes | No | No | Possible | Yes |
| Rectal Bleeding | No | No | No | Possible | Possible |
Possible investigations
Likely: Urinalysis, FBC, ESR/CRP, MSU, H. pylori testing
Possible: U&E, LFT, amylase, coeliac screen, CA-125, FIT, faecal calprotectin, plain abdominal X-ray, ultrasound, renal imaging, hospital-based lower GI investigations, gastroscopy.
Small Print: Specialised investigations such as mesenteric angiography and further tests for rare medical causes.
- Urinalysis: Blood alone with stone; blood, pus cells and nitrite in UTI.
- MSU: To confirm urinary infection and guide treatment.
- FBC and ESR/CRP: May suggest inflammatory bowel disease, PU or malignancy. Raised platelets associated with oesophageal or stomach cancer.
- U&E may be deranged in hydronephrosis, renal stones or Addison’s disease.
- LFT and amylase: LFT may be abnormal if carcinoma present. Amylase may be raised in pancreatitis and bowel ischaemia.
- Coeliac screen: Anti-endomysial and anti-gliadin antibodies – suggest coeliac disease if positive.
- CA-125: Especially in women aged 50 or more, may help exclude ovarian cancer.
- H. pylori testing: Strong association with peptic ulcer disease.
- FIT: A useful colorectal cancer ‘rule out’ test in patients at low risk. Also commonly required now when arranging a two-week referral to help secondary care stratify urgency of investigation.
- Faecal calprotectin: To help rule out inflammatory bowel disease, especially if recurrent or persistent diarrhoea is also a feature.
- Plain abdominal X-ray: May reveal constipation, subacute obstruction or kidney stones.
- Renal imaging: For renal stones or recurrent UTI.
- Ultrasound: Will show hydronephrosis and gallstones. Pelvic/abdominal ultrasound also indicated if CA-125 elevated.
- Hospital-based lower GI investigations: For various lower bowel disorders.
- Gastroscopy: May be required to confirm PU and exclude gastric carcinoma.
- Further tests such as angiography (for mesenteric ischaemia) or investigations for rare medical causes may be arranged after specialist referral.
Top Tips
- Simply establishing what provokes or relieves the problem can provide helpful pointers – pain occurring after eating suggests gallstones, PU, gastric carcinoma or mesenteric ischaemia; if relieved by defecation, the likely diagnoses are IBS or constipation.
- In an otherwise well patient, the longer the history the less likely there is to be significant underlying disease.
- Avoid repeated investigation if a patient has already been thoroughly assessed in the past – unless the individual becomes unwell or develops new symptoms. Be frank with the patient by explaining that doing more of the same will not change the outcome in investigating chronic unexplained abdominal pain.
- Be prepared to make a positive diagnosis of IBS in a fit young patient if the symptoms are classical and basic investigations are negative; explanation and education are the keys to effective management.
Red Flags
- Weight loss in association with recurrent abdominal pain suggests significant pathology.
- Hard enlarged left supraclavicular nodes (Troisier’s sign) are pathognomic of gastric carcinoma.
- Beware that constipation itself is often a symptom rather than a diagnosis. Be sure to establish and treat any underlying cause if it doesn’t respond to simple treatment.
- IBS is the commonest diagnosis – but consider other possibilities if the pain is always in the same site, wakes the patient at night or is associated with rectal bleeding or weight loss.