Milk is constipating to guinea pigs.
"The Vitamine Manual"
Walter H. Eddy
He says-"To avoid the constipating effects, I have always had mixed, before baking, one part of prepared oatmeal with two parts of flour, this compound I have found both nourishing, and regulating to the bowels.
"Advice to a Mother on the Management of her Children"
Pye Henry Chavasse
Our modern diet is by its "de-"nature, very constipating.
"How and When to Be Your Own Doctor"
Dr. Isabelle A. Moser with Steve Solomon