Beyond Normal: 5 Bloodwork Markers You Should Pay Attention To

Why You Should Read This

Your labs are back. Everything looks normal. But something still feels off.

This is where many patients spend years without answers. Here are five specific things standard bloodwork can miss and how to look for a more complete picture.

1. What Standard Bloodwork Actually Measures

When your doctor orders routine labs, they are typically looking at a defined set of markers: kidney function, liver enzymes, blood cell counts, electrolytes, and blood sugar. These are valuable. They catch a meaningful range of systemic disease.

What they are not designed to detect:

• Functional GI conditions like IBS, functional dyspepsia, or motility disorders. None of these leave a reliable fingerprint in standard serum panels.
• Early inflammatory bowel disease. CRP and ESR, markers of systemic inflammation, may be normal in early or mild IBD. A normal CRP does not rule out Crohn's disease or ulcerative colitis.
• Celiac disease, unless your physician specifically orders tissue transglutaminase IgA antibodies. It is not part of a standard panel and is frequently missed for years as a result.
• Small intestinal bacterial overgrowth (SIBO), which requires breath testing, not bloodwork.
• Gastroparesis and other motility disorders, which require specialized gastric emptying studies.

2. The Markers Worth Asking About

If you have ongoing GI symptoms and standard labs have come back normal, there are specific additional markers worth discussing with your physician.

• Fecal calprotectin is a stool-based marker of intestinal inflammation. It is one of the more sensitive tools for distinguishing inflammatory bowel disease from functional conditions like IBS. It is not a standard order, and most patients have never heard of it.
• Tissue transglutaminase IgA (tTG-IgA) is the primary screening test for celiac disease. If you have not been tested and you have chronic bloating, diarrhea, or unexplained fatigue, this is worth requesting explicitly.
• Fecal elastase measures pancreatic enzyme output and can identify exocrine pancreatic insufficiency, a frequently overlooked cause of malabsorption, loose stools, and weight loss.
• H. pylori testing, either via stool antigen or breath test, detects a bacterial infection in the stomach lining that causes ulcers and is classified as a carcinogen. It does not show up in routine bloodwork.
• SIBO breath testing measures hydrogen and methane gas produced by bacteria in the small intestine. Bloating, early satiety, and irregular bowel habits that have not responded to dietary changes are reasonable indications to pursue this.

3. Why These Tests Are Not Ordered Automatically

This is a fair question, and the answer is not that your physician is missing something obvious.

Primary care visits are time-constrained. Standard panels are designed to screen broadly and efficiently across a wide range of conditions. Specialized GI testing is typically ordered when there is a specific clinical indication, which often means symptoms need to be persistent, documented, and clearly communicated before the workup expands.

• The burden of history falls on the patient more than most people realize. A physician ordering labs from a brief annual visit is working with limited information. A patient who arrives with a documented symptom timeline is far more likely to get a targeted workup.
• Gastroenterology referral is often the appropriate next step when primary care labs are normal but symptoms persist. A GI specialist has a different toolkit and a different index of suspicion than a generalist.
• Symptoms that have been present for more than four to six weeks, are progressive, or are accompanied by unintentional weight loss, rectal bleeding, or nighttime symptoms warrant evaluation beyond routine labs regardless of prior normal results. Those are not cases to wait out.

4. What a More Complete GI Workup Can Look Like

Depending on the clinical picture, a thorough GI evaluation may include some combination of the following:

• Upper endoscopy (EGD) to evaluate the esophagus, stomach, and upper small intestine directly. Biopsies taken during this procedure can identify celiac disease, H. pylori, and other mucosal abnormalities that are invisible to bloodwork.
• Colonoscopy to evaluate the colon and terminal ileum. This remains the most direct way to assess for IBD, polyps, and colorectal pathology.
• Imaging, including CT enterography or MRI enterography, for small bowel evaluation in suspected Crohn's disease or other small intestinal pathology.
• Gastric emptying scintigraphy when gastroparesis is suspected based on symptoms of early satiety, nausea, and vomiting without a clear structural cause.

The right workup depends on the clinical picture. But the starting point is knowing that normal bloodwork is a beginning, not a conclusion.

Until next time,
Dr. Tabibian