Can a patient have Irritable Bowel Syndrome (IBS) or celiac disease with no hallmark symptoms aside from persistent floating stools?

Can IBS or Celiac Disease Present with Only Persistent Floating Stools?

Yes, both IBS and celiac disease can present with minimal or atypical symptoms, including isolated stool changes like persistent floating stools, though this presentation alone is insufficient for diagnosis and warrants systematic evaluation to exclude organic disease.

Understanding Floating Stools in Context

Floating stools typically indicate increased fat content (steatorrhea) or gas, which can occur in malabsorptive conditions like celiac disease or functional disorders like IBS. However, this single symptom lacks specificity and requires careful evaluation 1.

Celiac Disease with Minimal Symptoms

Atypical Presentations Are Common

• Celiac disease frequently presents without classic malabsorptive symptoms (diarrhea, weight loss, severe abdominal pain), and many patients have subtle or isolated gastrointestinal complaints 1.
• The disease can manifest with minimal symptoms while still causing villous atrophy and long-term complications if untreated 1.
• Studies show that 2.1% of patients with IBS-like symptoms actually have undiagnosed celiac disease, compared to 0.8% of controls 1.

Mandatory Screening Approach

• All patients with chronic gastrointestinal symptoms, including isolated stool changes, should undergo celiac serology testing with IgA tissue transglutaminase (IgA-tTG), which offers the best performance characteristics among serologic tests 1.
• The British Society of Gastroenterology strongly recommends celiac serology in all patients being evaluated for IBS-like symptoms, even without classic features 1.
• If serology is positive, small bowel biopsy remains the gold standard for diagnosis 1.

Critical Pitfall

Testing must occur while the patient is consuming gluten, as sensitivity of serologic tests is reduced on a gluten-free diet 1. Many patients self-restrict gluten before evaluation, leading to false-negative results.

IBS with Minimal Symptoms

Diagnostic Criteria Flexibility

• IBS diagnosis requires abdominal pain or discomfort associated with altered bowel habit for at least 6 months, but the NICE definition is more pragmatic than Rome IV criteria and may better capture real-world presentations 1.
• While abdominal pain is technically a "necessary diagnostic criterion," the intensity and frequency can vary significantly, and some patients may not emphasize pain as their primary complaint 1.

Positive Diagnosis After Exclusion

• IBS should be diagnosed positively based on symptoms only after excluding organic disease through appropriate testing 1.
• Required baseline testing includes: full blood count, C-reactive protein or ESR, celiac serology, and in patients under 45 with diarrhea, fecal calprotectin to exclude inflammatory bowel disease 1.
• Colonoscopy is not routinely indicated unless alarm features are present or the patient has risk factors for microscopic colitis (age ≥50, female sex, autoimmune disease, nocturnal diarrhea, weight loss) 1.

Algorithmic Approach to Persistent Floating Stools

Step 1: Initial Laboratory Evaluation

• Complete blood count (to assess for anemia suggesting malabsorption or inflammation) 1
• C-reactive protein or ESR (to screen for inflammatory processes) 1
• IgA tissue transglutaminase antibody (mandatory celiac screening) 1
• Fecal calprotectin if patient is under 45 years old (to exclude IBD) 1

Step 2: Assess for Alarm Features

• Weight loss, rectal bleeding, nocturnal symptoms, fever, or family history of IBD/colorectal cancer warrant urgent referral and endoscopic evaluation 1.
• Age over 50 with new-onset symptoms requires consideration of colonoscopy to exclude microscopic colitis and malignancy 1.

Step 3: Consider Additional Testing Based on Clinical Context

• Bile acid malabsorption testing (serum 7α-hydroxy-4-cholesten-3-one or SeHCAT scanning where available) should be considered in patients with watery diarrhea, especially those with prior cholecystectomy or nocturnal diarrhea 1.
• Stool studies for Giardia if travel history or exposure risk exists 1.
• Lactose and fructose breath testing if dietary triggers are suspected 1.

Step 4: Diagnostic Conclusion

• If celiac serology is positive: proceed to upper endoscopy with duodenal biopsies 1.
• If all testing is negative and no alarm features: diagnose IBS and initiate empiric therapy 1.
• If symptoms persist despite negative workup and IBS treatment: consider referral to gastroenterology for further evaluation, including possible colonoscopy to exclude microscopic colitis 1.

Key Clinical Insights

The Overlap Problem

• Symptoms of IBS and celiac disease are often indistinguishable, particularly when diarrhea, bloating, or abdominal pain predominate 2, 3, 4.
• Research demonstrates that 11-12% of patients initially diagnosed with IBS actually have celiac disease when systematically tested 5, 3.
• After initiating a gluten-free diet, celiac patients misdiagnosed as IBS show significant symptom improvement within 6 months 5, 3.

Nonceliac Gluten Sensitivity

• A subset of patients without celiac disease may have gluten sensitivity causing IBS-like symptoms and may benefit from gluten restriction 2, 4.
• This diagnosis requires negative celiac serology, normal or near-normal small bowel biopsy, and symptomatic response to gluten-free diet 4.

Discoverable Causes of IBS-D

• At least two-thirds of IBS-D cases have identifiable underlying mechanisms: food intolerances (30-40%), bile acid diarrhea (20-30%), or disturbed microbial flora (15-20%) 6.
• Making a "positive diagnosis" based on symptoms alone without excluding these conditions may miss treatable causes 6.

Common Pitfalls to Avoid

• Never diagnose IBS without celiac serology testing, as this is the most commonly missed organic diagnosis in patients with IBS-like symptoms 1.
• Do not assume floating stools alone indicate fat malabsorption; they can result from increased intestinal gas in functional disorders 6.
• Avoid premature closure on IBS diagnosis in patients over 50 or those with atypical features (nocturnal symptoms, weight loss, short duration of symptoms) without colonoscopy to exclude microscopic colitis 1.
• Remember that normal inflammatory markers (CRP, ESR) do not exclude celiac disease, as it is not primarily an inflammatory condition 1.