Olestra
Minerals such as calcium, iron, and magnesium are absorbed in the gastrointestinal tract without being digested first.
cholesterol
Monosaccharides (such as glucose and fructose), amino acids, fatty acids, vitamins, and minerals can be absorbed without first being digested in the human gastrointestinal tract. These nutrients are small enough to pass through the lining of the small intestine directly into the bloodstream. This process is facilitated by specific transport mechanisms for each type of nutrient. However, larger molecules like disaccharides and proteins require digestion by enzymes before they can be absorbed.
It comes out the other end.
Alcohol (ethanol) can diffuse from the digestive tract into the bloodstream without being digested. This is why alcohol can quickly enter the bloodstream and reach the brain, leading to its effects on the central nervous system.
cellulose which is present in grass can be digested by ruminants but cannot be digested by humans
Glucose
Glucose, if you're a diabetic with a rectal bleed.
water
no it cant digest it just goes right through you
No, bleaching synthetic fabric can cause damage to the material.
Glucose and fructose.