Protocol Overview

Digestive Health Protocol: Gut Inflammation, Celiac Screening & Liver Markers

Q: Should I get a colonoscopy if my blood tests are normal?

Normal blood tests don't fully rule out colorectal pathology. Colonoscopy is recommended for age-appropriate screening (45+ per USMSTF guidelines), alarm symptoms (rectal bleeding, unexplained weight loss, family history of colorectal cancer), or persistent change in bowel habits regardless of blood results.

Q: What does elevated ALT mean if I don't drink alcohol?

Non-alcoholic fatty liver disease (now called MASLD) is the most common cause of elevated ALT in non-drinkers. It's strongly associated with insulin resistance, obesity, and metabolic syndrome. FIB-4 score (calculated from age, ALT, AST, and platelets) helps assess fibrosis risk non-invasively.

The digestive system is a major interface between your body and the outside world, and its dysfunction manifests across seemingly unrelated symptoms: fatigue, iron deficiency, joint pain, skin conditions, and mood changes can all trace back to gut pathology. Blood tests and stool markers now identify celiac disease, inflammatory bowel disease, liver fibrosis, and H. pylori infection with high accuracy — often before symptoms become severe. Fecal calprotectin distinguishes inflammatory from functional bowel disease without endoscopy. Tissue transglutaminase IgA (tTG-IgA) screens for celiac disease with >95% sensitivity. ALT and GGT track liver inflammation, while the FIB-4 score non-invasively stages fibrosis. Combined with colonoscopy and gastroscopy findings, these markers form a comprehensive picture of gastrointestinal health.

📅Last updated: May 31, 2026•📚Evidence-informed content•🔬Editorial policy

Key Biomarkers

The biomarkers that define this protocol

Fecal Calprotectin

Non-invasive stool marker that distinguishes IBD from IBS with high accuracy.

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tTG-IgA

Primary celiac disease screening test with >95% sensitivity.

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ALT

Liver cell damage marker; elevated in fatty liver, hepatitis, and metabolic dysfunction.

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GGT

Liver and biliary marker; sensitive to alcohol use and metabolic syndrome.

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hs-CRP

Systemic inflammation marker used to monitor IBD activity alongside calprotectin.

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Ferritin

Iron stores — unexplained iron deficiency is a red flag for celiac disease or GI blood loss.

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Common Patterns

Patterns we see across real lab reports

Unexplained iron deficiency with normal CBC should trigger celiac screening (tTG-IgA).
Elevated fecal calprotectin (>250 μg/g) with chronic diarrhoea strongly suggests IBD over IBS.
Elevated ALT with metabolic risk factors (obesity, insulin resistance) points to MASLD/fatty liver.
GGT elevation disproportionate to ALT/AST suggests biliary pathology or alcohol use.
Persistent dyspepsia with positive H. pylori stool antigen warrants eradication therapy.
Normal calprotectin (<50 μg/g) with abdominal symptoms effectively rules out significant intestinal inflammation.

90-Day Protocol

What a 90-day protocol includes

Celiac screening (tTG-IgA + total IgA) for unexplained iron deficiency, chronic diarrhoea, or family history.
Fecal calprotectin to differentiate IBD from IBS before endoscopy referral.
Liver panel (ALT, AST, GGT, ALP) with FIB-4 score for metabolic liver disease screening.
H. pylori stool antigen test for persistent dyspepsia (not serology alone).
Colonoscopy and gastroscopy result interpretation and surveillance scheduling.
Vitamin D, B12, folate, and ferritin assessment for malabsorption screening.

Example Priorities

A preview of how we prioritize action

tTG-IgA

Critical

Current85 U/mL

Target<10 U/mL

ALT

Suboptimal

Current58 U/L

Target<30 U/L (optimal)

Fecal Calprotectin

Critical

Current320 μg/g

Target<50 μg/g

Medical

Refer to gastroenterologist if tTG-IgA is elevated or fecal calprotectin is persistently >250 μg/g.
Screen for H. pylori with stool antigen if persistent dyspepsia or peptic ulcer history.
Calculate FIB-4 score if ALT is elevated with metabolic risk factors.

Diet

Strict gluten-free diet is the only treatment for confirmed celiac disease.
Mediterranean diet reduces liver fat and improves ALT in MASLD.
Fibre-rich diet supports gut microbiome diversity and reduces inflammation markers.

Lifestyle

Limit alcohol to reduce GGT and liver inflammation.
Weight loss of 7-10% body weight significantly improves MASLD.
Regular exercise reduces systemic inflammation and improves gut motility.

This is an illustrative preview, not medical advice.

Next Step

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Explore a full demo protocol or upload your labs to get a personalized plan.

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FAQ

Frequently asked questions

What blood tests should I ask for if I have chronic digestive symptoms?

Start with: CBC (for anaemia), CMP (liver function), tTG-IgA + total IgA (celiac screen), CRP (inflammation), and ferritin (iron stores). If diarrhoea-predominant, add fecal calprotectin (stool test). If dyspepsia, add H. pylori stool antigen.

Can blood tests diagnose IBS?

IBS is a diagnosis of exclusion — blood tests rule out conditions that mimic IBS (celiac disease, IBD, thyroid dysfunction). A normal fecal calprotectin (<50 μg/g) effectively rules out significant intestinal inflammation and supports an IBS diagnosis.

Should I get a colonoscopy if my blood tests are normal?

Normal blood tests don't fully rule out colorectal pathology. Colonoscopy is recommended for age-appropriate screening (45+ per USMSTF guidelines), alarm symptoms (rectal bleeding, unexplained weight loss, family history of colorectal cancer), or persistent change in bowel habits regardless of blood results.

What does elevated ALT mean if I don't drink alcohol?

Non-alcoholic fatty liver disease (now called MASLD) is the most common cause of elevated ALT in non-drinkers. It's strongly associated with insulin resistance, obesity, and metabolic syndrome. FIB-4 score (calculated from age, ALT, AST, and platelets) helps assess fibrosis risk non-invasively.

Sources

References & Further Reading

Primary citations supporting Digestive Health:

Our content is informed by peer-reviewed research, clinical guidelines, and authoritative health sources. Additional references include:

PubMed / MEDLINE — Peer-reviewed biomedical literature
UpToDate — Evidence-based clinical decision support
StatPearls / NCBI Bookshelf — Clinical reference summaries
Lab Tests Online (AACC) — Patient-focused lab test information

For specific citations or questions about our content, please contact us or review our editorial policy.

Digestive Health Protocol: Gut Inflammation, Celiac Screening & Liver Markers

📅Last updated: May 31, 2026•📚Evidence-informed content•🔬Editorial policy

Patterns we see across real lab reports

Unexplained iron deficiency with normal CBC should trigger celiac screening (tTG-IgA).

Elevated fecal calprotectin (>250 μg/g) with chronic diarrhoea strongly suggests IBD over IBS.

Elevated ALT with metabolic risk factors (obesity, insulin resistance) points to MASLD/fatty liver.

GGT elevation disproportionate to ALT/AST suggests biliary pathology or alcohol use.

Persistent dyspepsia with positive H. pylori stool antigen warrants eradication therapy.

Normal calprotectin (<50 μg/g) with abdominal symptoms effectively rules out significant intestinal inflammation.

What a 90-day protocol includes

Celiac screening (tTG-IgA + total IgA) for unexplained iron deficiency, chronic diarrhoea, or family history.

Fecal calprotectin to differentiate IBD from IBS before endoscopy referral.

Liver panel (ALT, AST, GGT, ALP) with FIB-4 score for metabolic liver disease screening.

H. pylori stool antigen test for persistent dyspepsia (not serology alone).

Colonoscopy and gastroscopy result interpretation and surveillance scheduling.

Vitamin D, B12, folate, and ferritin assessment for malabsorption screening.

A preview of how we prioritize action

tTG-IgA

Critical

Current85 U/mL

Target<10 U/mL

ALT

Suboptimal

Current58 U/L

Target<30 U/L (optimal)

Fecal Calprotectin

Critical

Current320 μg/g

Target<50 μg/g

Medical

Refer to gastroenterologist if tTG-IgA is elevated or fecal calprotectin is persistently >250 μg/g.
Screen for H. pylori with stool antigen if persistent dyspepsia or peptic ulcer history.
Calculate FIB-4 score if ALT is elevated with metabolic risk factors.

Diet

Strict gluten-free diet is the only treatment for confirmed celiac disease.
Mediterranean diet reduces liver fat and improves ALT in MASLD.
Fibre-rich diet supports gut microbiome diversity and reduces inflammation markers.

Lifestyle

Limit alcohol to reduce GGT and liver inflammation.
Weight loss of 7-10% body weight significantly improves MASLD.
Regular exercise reduces systemic inflammation and improves gut motility.

This is an illustrative preview, not medical advice.

Frequently asked questions

What blood tests should I ask for if I have chronic digestive symptoms?

Can blood tests diagnose IBS?

Should I get a colonoscopy if my blood tests are normal?

What does elevated ALT mean if I don't drink alcohol?

References & Further Reading

Primary citations supporting Digestive Health:

Our content is informed by peer-reviewed research, clinical guidelines, and authoritative health sources. Additional references include:

PubMed / MEDLINE — Peer-reviewed biomedical literature

UpToDate — Evidence-based clinical decision support

StatPearls / NCBI Bookshelf — Clinical reference summaries

Lab Tests Online (AACC) — Patient-focused lab test information

For specific citations or questions about our content, please contact us or review our editorial policy.

Digestive Health Protocol: Gut Inflammation, Celiac Screening & Liver Markers

The biomarkers that define this protocol

Fecal Calprotectin

tTG-IgA

ALT

GGT

hs-CRP

Ferritin

Patterns we see across real lab reports

What a 90-day protocol includes

A preview of how we prioritize action

tTG-IgA

ALT

Fecal Calprotectin

Medical

Diet

Lifestyle

See your protocol in action

Explore related protocols

Inflammation

Metabolic Health

Vitamins & Minerals

Frequently asked questions

References & Further Reading

Digestive Health Protocol: Gut Inflammation, Celiac Screening & Liver Markers

The biomarkers that define this protocol

Fecal Calprotectin

tTG-IgA

ALT

GGT

hs-CRP

Ferritin

Patterns we see across real lab reports

What a 90-day protocol includes

A preview of how we prioritize action

tTG-IgA

ALT

Fecal Calprotectin

Medical

Diet

Lifestyle

See your protocol in action

Explore related protocols

Inflammation

Metabolic Health

Vitamins & Minerals

Frequently asked questions

References & Further Reading