How long does it take to digest lettuce?

Lettuce is typically digested within 24 to 72 hours. Only bulkier foods, like nuts and celery, digest at somewhat slower rates in the stomach, but pass through the digestive system more easily after being digested by the stomach.

The stomach digests all foods, even bulky ones like nuts and celery, in no more than three hours, Healthy bowels do not differentiate between types of food; they digest everything - steak, bacon, salads, fruits, dairy - together at the exact same rate once they pass into the intestines. All foods, even the highly-processed and easily-digested varieties, exit the body within three days.