Most people recognize that thin, fair skinned women are prone to osteoporosis, as are patients chronically taking steroids and those who have had prolonged episodes of amenorrhea. One etiology of osteoporosis to not overlook is chronic diarrhea.
Chronic diarrhea causes a loss of bicarbonate leading to a chronic low-level metabolic acidosis. This can often be picked up on a basic metabolic panel by seeing a low bicarb and possibly low potassium. This chronic metabolic acidosis can cause osteoporosis.
This has even been studied in pre-menopausal patients with cystic fibrosis. Cystic fibrosis patients have pancreatic insufficiency and therefore have a chronic diarrhea marked by steatorrhea. Most of these patients had osteopenia and some had osteoporosis.