I used to work in a hospital, and the gastroenterology department did a lecture back in the 90s on treating constipation and why laxatives are a BAD thing. They were however very positive about fibre, especially soluble fibre. (They also explained that from a medical view point a diagnosis of constipation/diarrhea is based on how much water is in your stool, not on frequency of bowel movements.) To quote from the Mayo Clinic: "Soluble fiber is found in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium." My experience is that you have to eat a whole lot more legumes, fruits, etc than I want to eat to get enough fibre. So I just take psyllium. I started with Metamucil, but was horrified to discover, remember this was back in the 90s, that it was 50% sugar! So I hunted around and now either just buy psyllium from the bulk foods store or health store or I go to my friendly neighbourhood Indian market and buy it as Telephone Brand Psyllium Husk (Sat-Isabgol). Start with a very small amount, like 1/4 teaspoon (1 ml) in a glass of cold water twice a day and increase gradually until you have the results you want. It is not a taste treat. I frankly find it tasteless, but some people can't stand the flavour. Be careful not to start with too much or increase too fast, or you'll have the opposite problem.