what can cause change in stool diameter
Here's a guide to some of the most likely â and most lethal â conditions that can lead to changes in the shape, size, smell and shade of your stool. Shape. Insufficient fiber in the diet, diverticulosis, bowel spasm or excessive straining are common causes of a change in stool shape. Diverticulosis causes pothole-like craters in the lining of the colon, as well as a narrowing of the internal diameter of the colon due to wall thickening.