What are some good, natural ways to relieve constipation for someone who already takes steps to drink a lot of water and eat a lot of fiber? Instead of day's worth of poop daily, I typically have three day's worth every three days and nothing in between.

The short version: when fiber and water are already high, the next step is to change the type of fiber and add movement, not to eat more of the same.

The evidence here shows that adding more generic fiber to an already high-fiber diet may not help much. A 2010 study in constipated children found that fiber-fortified snacks and inulin drinks increased fiber intake but produced only modest and inconsistent improvements in stool frequency [1]. The difference was small and not statistically significant in the main analysis [1]. This matches the pattern: once you are getting enough fiber, the type matters more than the amount.

What does work, based on the retrieved studies, is switching to specific fibers and adding physical strategies. A 2025 review found that kiwifruit (2-3 daily) increased stool frequency more than psyllium, by about 0.36 extra bowel movements per week [2, 3]. The same review reported that psyllium itself improved response to treatment by about 82% compared to placebo (RR 1.82) [3]. Prunes also improved stool consistency [3]. A 2025 randomized trial found that synbiotics (probiotic plus prebiotic) doubled weekly bowel frequency from about 2.8 to 5.9 over 8 weeks [2]. Abdominal massage added about 1.6 extra bowel movements per week in a meta-analysis [2]. Regular physical activity shortened colonic transit time from about 79 to 58 hours in a 12-week program [4].

Magnesium oxide is another option: a meta-analysis found it increased stool frequency by about 3.7 bowel movements per week (MD 3.72) [3]. That is a large effect, but it is a supplement, not a food. Start low and watch for loose stools.

My call: try 2-3 kiwifruit daily, add a psyllium supplement, and do 10-15 minutes of abdominal massage each morning. If that is not enough, consider a synbiotic or magnesium oxide. Confidence: moderate — the evidence comes from reviews and trials, but individual response varies.