The simplest test: the toilet bowl

The Bristol scale, and what the bowl teaches you every day.

The most direct feedback on what you eat, you get every day in the bathroom. An “ideal” stool is long, smooth and in one piece — anaconda style — and easy to pass without straining. It is the sign that there is enough fiber, enough water and a transit at the right pace.

The paper gives a complementary clue, and it is fairly reliable in practice: a well-formed stool leaves few traces, a sticky or pasty stool leaves many — the usual sign of too fast a transit, too little fiber or too much fat. Just know that, unlike the scale below, this is not a criterion standardized by research: it is a useful observation, not a measurement.

Doctors actually classify stools into 7 types, on what is called the Bristol scale: types 1–2 = hard lumps or lumpy sausage (transit too slow, lack of fiber or water); types 3–4 = smooth sausage or with slight cracks — the ideal zone, the anaconda; types 5–7 = soft pieces to liquid (transit too fast, or a poorly tolerated food).

And contrary to the received image, a stool is not made of “meal leftovers”: it is about 75% water, and in the rest, the bacteria of your microbiota — dead and alive — account roughly for a quarter to half of the dry weight, along with undigested fibers. Your microbiota renews itself constantly: feeding it well literally shows in the bowl.

Blood, pain, diarrhea or constipation that last: there, it is no longer a question of fiber — talk to a doctor.