Fiber blends, which typically contain a mix of soluble and insoluble fibers from sources like psyllium husk, oat bran, and other plant materials, are scientifically validated for supporting rectal and overall colon health. Dietary fiber increases stool bulk, softens stool, and promotes regular bowel movements, thereby reducing straining during defecation. This effect can help prevent or manage common rectal issues, including hemorrhoids, anal fissures, and constipation. Numerous randomized controlled trials and meta-analyses confirm that fiber supplementation is effective in relieving chronic constipation and improving stool form and frequency. For example, studies have shown that psyllium, a common fiber blend ingredient, significantly increases stool frequency and reduces the need for laxatives. The mechanism is well understood: fiber absorbs water, increases stool mass, and stimulates peristalsis, thereby enhancing rectal evacuation. Additionally, increasing fiber intake is a first-line recommendation in clinical practice guidelines for the prevention and treatment of hemorrhoids and mild to moderate constipation. However, while fiber blends are effective in supporting the rectal body system, their efficacy can vary depending on the specific type of fiber and the underlying cause of rectal symptoms. Overall, the use of fiber blends is strongly supported by scientific evidence for promoting rectal and lower gastrointestinal tract health.