What is the recommended evaluation for a patient with persistent floating stools, normal complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid function tests, liver enzymes, iron panel including ferritin, and amylase and lipase levels, without abdominal pain, diarrhea, or weight loss?

Evaluation of Persistent Floating Stools with Normal Laboratory Studies

In a 41-year-old woman with isolated floating stools for three months, well-formed normal-colored stools, and comprehensive normal laboratory testing including CBC, CMP, thyroid, liver enzymes, iron panel, and pancreatic enzymes, reassurance is the primary recommendation with selective testing for celiac disease and fecal calprotectin only. 1

Reassuring Clinical Features

This patient presents with multiple reassuring features that argue strongly against significant organic pathology:

• Normal complete blood count excludes anemia, which would be expected with iron, folate, or B12 malabsorption from small bowel disease 2
• Normal iron panel (including ferritin) directly excludes iron malabsorption, the most sensitive early marker of small bowel pathology 2
• Normal liver enzymes and amylase/lipase exclude pancreatic insufficiency, which would present with severe steatorrhea and weight loss, not isolated floating stools 2
• Well-formed, normal-colored stools are a good prognostic sign and differ significantly from true steatorrhea (greasy, foul-smelling, difficult-to-flush stools) 1
• Absence of alarm features including no weight loss, no blood in stools, no abdominal pain, no diarrhea, and no jaundice 3

Understanding Floating Stools

Floating stools are commonly associated with functional bowel disorders rather than organic disease:

• Floating stools occur in 26% of patients with functional bowel disorders, particularly mixed irritable bowel syndrome, and are not associated with abnormal colonic transit times or psychological disorders 4
• The patient's occasional mild constipation aligns with this functional pattern 4
• True malabsorption presents with additional features including weight loss, steatorrhea (greasy, foul-smelling stools), and nutritional deficiencies—none of which are present here 1

Recommended Selective Testing

Despite the reassuring presentation, two specific tests are warranted:

Celiac Disease Screening

• Tissue transglutaminase IgA antibodies with total IgA level should be checked, as celiac disease can present with subtle symptoms and is the most common small bowel enteropathy in European populations 3, 5, 1
• This test must be performed before any gluten restriction, as dietary changes will cause false-negative results 5

Inflammatory Bowel Disease Screening

• Fecal calprotectin should be tested to exclude subclinical inflammatory bowel disease, particularly given the chronic nature of symptoms 5, 1
• This non-invasive test has high specificity for organic disease and can guide the need for further investigation 2

Tests NOT Recommended

Several tests should be explicitly avoided in this clinical scenario:

• Colonoscopy is not indicated unless the patient is over age 50 and not up-to-date with colorectal cancer screening, or alarm features develop 3, 1
• Fecal fat testing is reserved for suspected steatorrhea, not floating stools with normal-appearing stool 2
• Fecal elastase is only indicated for suspected pancreatic insufficiency, which presents with severe steatorrhea and weight loss—not this clinical picture 2
• Upper endoscopy is only indicated if celiac serology is positive or upper gastrointestinal symptoms develop 5
• Stool for ova and parasites is only recommended with travel history or endemic area exposure 1

Clinical Management Approach

If the selective testing (celiac serology and fecal calprotectin) returns normal:

• Provide reassurance that floating stools alone, without alarm features, do not indicate serious pathology 1
• Address the mild constipation with dietary fiber increase (15 g daily psyllium) and adequate hydration 3
• Consider a therapeutic trial of fiber supplementation, which costs approximately $1 or less daily 3

Alarm Features Requiring Immediate Re-evaluation

The patient should return immediately if any of the following develop:

• Unintentional weight loss >5% body weight 1
• Change in stool character to true steatorrhea (greasy, foul-smelling, difficult to flush) 1, 2
• Rectal bleeding or positive fecal occult blood 1
• New laboratory abnormalities, particularly anemia, hypoalbuminemia, or elevated inflammatory markers 2
• Nocturnal symptoms that wake the patient from sleep 1
• Development of abdominal pain, fever, or systemic symptoms 3, 1

Critical Pitfalls to Avoid

• Do not pursue extensive workup in young patients with functional symptoms and normal initial investigations, as this leads to unnecessary costs and patient anxiety 1
• Do not perform celiac testing after starting a gluten-free diet, as this causes false-negative results 5
• Do not delay colonoscopy if alarm features develop, even in younger patients 5
• Do not attribute symptoms to dietary deficiency alone without excluding gastrointestinal pathology if new features develop 5