Which of the following is not a characteristic of normal bowel activity?

Heavy straining during defecation is not a characteristic of normal bowel activity. Normal bowel function typically involves regular and easy passage of stool without significant effort or discomfort. Straining can indicate issues such as constipation or an obstruction in the bowel. Individuals with healthy bowel habits should find the process of defecation to be relatively effortless, with stools passing smoothly and without the need for heavy abdominal pressure.

The other options describe aspects of healthy bowel movements. Regular passage of stool suggests a consistent digestion process, while having stools that are soft and formed indicates adequate hydration and fiber intake. Brown-colored stools generally reflect the normal breakdown of bilirubin, contributing to a healthy digestive process. Each of these characteristics is essential for assessing bowel health, unlike heavy straining, which typically signals potential problems.