It depends on the individual.

Of course, the pounds of encrusted fecal matter would be eliminated.

Of course, the body would better be able to absorb nutrients.

Whether those things would leads to weight loss or gain varies from individual to individual. If one is overweight, the improved nutrient absorption would properly nourish the body, thereby decreasing cravings for poorer food choices, which could lead to weight loss. I'm experiencing this, after a week on Oxypowder ; I've lost three-quarters of an inch from my hips in a week.

If one is underweight, the same improved nutrient absorption would also allow the body to be properly nourished, possibly leading to necessary weight gain.