Whole milk

Fibre exists only in plants, so milk contains none. That single fact explains why milk sits in the allowed column of every low-fibre leaflet compared for this book, and why several of them go further and recommend fortifying milk with milk powder to get more energy and protein into a small volume.

This book relies on that. Milk, cream, butter and cheese are what make these recipes rich enough to be worth eating when appetite is poor, and full fat is the default throughout rather than a lapse. See fortifying.

Where a restriction can come from

Lactose, which is a separate question from fibre. The enzyme that digests it is made in the lining of the small bowel, and when that lining is inflamed by pelvic radiotherapy or by treatment, less of it is available. Undigested lactose then draws water into the bowel and makes diarrhoea worse.

So advice written for pelvic radiotherapy or for after a low anterior resection can add a lactose restriction that a general low-fibre sheet does not mention. Both are correct. They are answering different questions.

What to use instead

Lactose-free milk, which is ordinary milk with the enzyme already added and behaves identically in a sauce, a custard or a shake. Every milk-based recipe here works on it without any other change. Hard cheese contains very little lactose and butter almost none, so those usually stay.

Plant milks are a poorer swap, since most carry less protein and some have added fibre. Check the label. See milk and lactose.