Can Thin Stools Be Normal?

Narrow stools that occur infrequently probably are harmless. However in some cases, narrow stools — especially if pencil thin — may be a sign of narrowing or obstruction of the colon due to colon cancer.

What does it mean when your poop is skinny?

While narrow or pencil-thin stool is not always a sign of constipation, it may be if your poop doesn't normally look that way. Constipation is usually caused by a lack of fiber in your diet or not enough exercise. Other causes include pregnancy, travel, use of some medications, and changes in your hormone levels.

What does your stool look like if you have colon cancer?

Black poop is a red flag for cancer of the bowel. Blood from in the bowel becomes dark red or black and can make poop stools look like tar. Such poop needs to be investigated further. Poop which is bright red may be a sign of colon cancer.