What should I know about stuhlgang zu hart kommt nicht raus?

The question concerns constipation (hard stool that is difficult to pass). The provided knowledge context contains no specific information on this topic – it primarily covers DNA variants (COMT, BDNF, FOXO3, PPARG) and stimulants (caffeine/alcohol). Therefore, I cannot derive an evidence-based answer from the given sources. General medical advice: a high-fiber diet (whole grains, fruits, vegetables), adequate fluid intake (about 1.5–2 L/day), and regular physical activity promote bowel function. For persistent constipation, medical causes (e.g., medications, hypothyroidism, slow transit) should be evaluated. Supplements like psyllium husk or macrogol may provide short-term relief but are not intended for long-term use. The evidence for these general recommendations is strong (guidelines), but it is not present in the provided context. Note: if blood in stool, severe pain, or weight loss occurs, seek medical evaluation. The evidence rating is 'unclear' because the context does not directly support this answer.