What is the recommended initial procedure for an adult patient with a history of gastrointestinal symptoms requiring gastroenterology evaluation?

Initial Gastroenterology Procedure for Adults with GI Symptoms

For adults with new gastrointestinal symptoms, the initial procedure depends critically on age and alarm features: patients over 45 years with new or changed dyspeptic symptoms require upper endoscopy (esophagogastroduodenoscopy) with biopsies, while younger patients without alarm features should first undergo non-invasive testing including faecal calprotectin measurement before proceeding to endoscopy. 1

Age-Based Stratification for Upper GI Symptoms

Patients Over 45 Years

• Proceed directly to upper endoscopy for any new onset or change in dyspeptic symptoms, regardless of alarm features, to avoid missing gastric cancer 1
• Upper endoscopy with systematic biopsies (6-8 specimens from multiple sites) is the appropriate initial procedure 2
• This age threshold reflects the significantly higher pretest probability of malignancy in this population 1

Patients Under 45 Years

The approach is more nuanced and depends on specific clinical features:

Immediate upper endoscopy is indicated if ANY of the following alarm features are present: 1, 3

• Progressive dysphagia
• Recurrent vomiting
• Evidence of gastrointestinal bleeding
• Unintentional weight loss
• Family history of GI malignancy

For patients under 45 WITHOUT alarm features: 1

• First obtain non-invasive H. pylori testing (serology)
• If H. pylori positive OR taking NSAIDs, proceed to upper endoscopy
• If severe and persistent symptoms despite treatment, proceed to endoscopy
• Defer endoscopy in mild symptoms responding to lifestyle modifications and antacids

Lower GI Symptoms: The Faecal Calprotectin Pathway

For patients aged 16-40 with new lower GI symptoms lasting >4 weeks where IBD is suspected: 1

Initial laboratory workup in primary care: 1

• Complete blood count
• Urea & electrolytes
• CRP
• Coeliac screen
• Stool culture

Faecal calprotectin measurement guides the next step: 1

• <100 µg/g: IBS likely; treat empirically in primary care
• 100-250 µg/g: Consider repeat testing or routine gastroenterology referral
• >250 µg/g: Urgent gastroenterology referral for colonoscopy

Critical exception: If rectal bleeding PLUS any of the following are present, bypass faecal calprotectin and refer via suspected cancer pathway: 1

• Abdominal pain
• Change in bowel habit
• Weight loss
• Iron deficiency anaemia
• Abdominal, rectal, or anal mass
• Unexplained anal ulceration

Colonoscopy as Initial Procedure

Ileocolonoscopy with biopsies is the necessary initial procedure when: 1

• IBD is suspected based on elevated faecal calprotectin (>250 µg/g) 1
• Patient is over 50 years with new lower GI symptoms (higher colon cancer risk) 1
• Alarm features are present at any age 1

Proper colonoscopy technique requires: 1, 2

• Visualization of terminal ileum and all colonic segments
• Minimum of 2 biopsies from each of 6 segments: terminal ileum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum 2
• Biopsies from both abnormal-appearing AND normal-appearing mucosa to document skip lesions 1, 2
• Photo documentation of lesions and anatomical landmarks 2

Upper Endoscopy Biopsy Protocol

When upper endoscopy is performed, systematic sampling is essential: 2, 3

• 6-8 total biopsies from multiple sites
• Two biopsies from each examined segment, including normal and abnormal areas 1, 3
• For suspected celiac disease: minimum 4 biopsies from second part of duodenum including bulb 2
• For gastric evaluation: separate biopsies from antrum and body 2

Common Clinical Pitfalls to Avoid

Do not defer endoscopy in patients over 45 years with new dyspeptic symptoms, even if they respond to empirical therapy—this is the most common age group for missing gastric cancer 1

Do not order colonoscopy in young patients with typical IBS symptoms (pain relieved by defecation, bloating, altered stool form) and normal faecal calprotectin—this represents inappropriate use of resources 1

Do not obtain inadequate biopsy specimens—taking fewer than the recommended minimum from multiple sites significantly reduces diagnostic accuracy for IBD 2

Do not skip H. pylori testing in younger patients with dyspepsia before considering endoscopy—serological testing has high negative predictive value and can guide management 1

Do not perform endoscopy in patients with uncomplicated heartburn responding to simple measures (lifestyle changes, antacids, alginates)—this is inappropriate and does not improve outcomes 1

Special Populations

Pediatric patients and adults with upper GI symptoms in the context of suspected Crohn's disease: 1, 3

• Upper GI endoscopy with biopsies is particularly useful
• Obtain biopsies from esophagus, stomach, and duodenum to document upper GI Crohn's involvement

Patients with suspected small bowel disease after negative upper and lower endoscopy: 1

• Small bowel capsule endoscopy (SBCE) is recommended when clinical suspicion remains high
• Enteroscopy is reserved for obtaining tissue when abnormalities are detected in areas inaccessible to standard endoscopy