Magen-Darm-Gesundheit: when to see a doctor?

You should see a doctor for gastrointestinal issues if you experience any of the following: blood in stool (visible or occult), unexplained weight loss, persistent diarrhea or constipation lasting more than two weeks, severe abdominal pain, heartburn with difficulty swallowing, or a family history of colorectal cancer or inflammatory bowel disease. New-onset food intolerance or suspected allergy also warrants medical evaluation before relying on home tests. At-home tests (e.g., fecal occult blood, microbiome analysis, DNA tests) can provide complementary information but are not substitutes for clinical diagnosis. Many such tests lack robust validation or only indicate sensitization without clinical correlation. Evidence for routine self-testing in asymptomatic individuals is weak. Acute warning signs like black tarry stools, vomiting blood, or signs of peritonitis require immediate medical attention. In summary, when in doubt or with risk factors, consult a gastroenterologist early.