Eating disorders, such as anorexia nervosa and bulimia nervosa are very common. These eating disorders are known to be associated with kidney stones.

In anorexia, the person has an intense fear of gaining weight and limits the food they eat. Eighty-five to ninety-five percent of these individuals are female and 1–4.2 % of women suffer from anorexia in their lifetime [11]. As a result of this disorder, fasting, vomiting and purging result in loss of fluids and minerals. The chronic dehydration and low potassium levels can lead to kidney stones and even renal failure. In anorexia nervosa, nephrolithiasis are composed most frequently of ammonium urate due to low urinary output and increased urinary ammonium output secondary to low urinary phosphate and diarrhea with hyperchloremic metabolic acidosis. Low urine output leading to high urinary uric acid, oxalate and calcium can lead to uric acid and calcium stones as well as nephrocalcinosis [12].

Bulimia is characterized by enormous consumption of food, followed by self-induced vomiting. Eighty-five to ninety percent of individuals with bulimia are women. Up to 4 % of females in the United States will have bulimia in their lifetime [13]. The individuals alternate between eating and purging. Urinary Calcium and Oxalate levels rise during eating and drop during the fasting phase.

In treating patients with eating disorders who make stones, the first issue is to address the underlying disease. These patients first need to address their eating disorder. Treating this may correct the risk of stones. Since eating disorders may be a life threatening condition, patients are encouraged to address this issue first. The psychological issues of this disorder are beyond the scope of this discussion.

Crohn’s disease is an inflammatory bowel disease that results in inflammation of the lining of the digestive tract. It affects men and women equally. In this disease, fat binds to calcium, leaving oxalate free to be absorbed and deposited in the kidney, where it can bind with calcium to form a stone. Their urine is more concentrated, a condition that is more likely to lead to stone formation. The risk of stones is greater than the general population and these individuals usually produce calcium oxalate stones [14]. Kidney stone treatment calls for an increased fluid intake together with a low-oxalate diet.

Patients with Crohn’s disease are also at risk for forming uric acid stones. This type of stone develops in acidic urine and this is caused by increased uric acid absorption in the injured colon. These patients can be treated with potassium citrate.

There is a higher prevalence of osteoporosis and a greater incidence of fractures in postmenopausal women than older men [15]. Osteoporosis is often referred to as a “woman’s disease”. Gender is a risk factor for osteoporosis and may be a risk factor for stones.

Women with a history of kidney stones may be at a greater risk of developing coronary heart disease [16]. This association or increased risk was not found in men. A possible explanation for this distinction may be hormonal differences between men and women.

The ureter has three anatomical narrowed areas along it’s course from the kidney to the bladder. First is the ureteropelvic juncture (or UPJ); the second area is the crossing iliac vessels; the third area is the ureterovesical juncture (or UVJ). These anatomical barriers for blocking the passage of a stone exist in both men and women.

In men with enlarging prostates, they may have an additional barrier that may prevent the passage of stones.