The 'not so short-bowel syndrome': potential health problems in patients with an ileostomy

The study aimed to determine whether an ileostomy compromises nutritional, hydration and electrolyte status and bone mineral density.

Body weight, body mass index (BMI) and fat and lean body mass (LBM) were measured in 60 patients with an ileostomy [14 small-bowel resection (SBR); 46 non-small-bowel resection (NSBR)] and in 60 age- and sex-matched normal controls. Measurement of plasma sodium, potassium, calcium, magnesium, urea and creatinine and 24-h urinary output of water, Na, K, Ca and Mg was made in 45 NSBR and 14 SBR ileostomists and in all the controls. Forty-six NSBR and 13 SBR ileostomists had bone mineral density (BMD) measurements of lumbar spine (LS) and femoral neck (FN).

The body weight of ileostomists was less than controls [median 67.8 (36.4-115.1) vs 77.7 (48.0-103.3) kg; P < 0.05]. BMI was also less [25.0 (14.3-43.0) vs 27.3 (20.2-32.2) kg/m(2) ; P < 0.05] with a lower LBM [47.8 (19.3-73.0) vs 52.9 (34.0-73.8) kg; P < 0.05]. The 24-h urinary output of the ileostomists was lower than for controls [1380 (430-4690) vs 2000 (840-4440) ml/24 h; P < 0.05] suggesting some degree of dehydration. In 62.7% of ileostomists 24-h urinary Na excretion was < 100 mmol/day vs 16.7% of controls, and ileostomists with lower urinary Na were more likely than ileostomists with normal Na excretion to have a low BMI [23.9 (14.3-33.0) vs 28.4 (16.6-43.0) kg/m(2) ; P < 0.001] and LBM [44.1 (19.3-73.0) vs 59.5 (36.6-67.9) kg; P < 0.001]. The respective 24-h output of Ca was [2.2 (0-6.1) vs 4.7 (0-13) mmol; P < 0.001] and Mg was [2.0 (0-13.7) vs 3.9 (1.2-5.4) mmol; P < 0.001], and BMD Z-score LS was -0.15 (-2.0 to 5.2) vs 0.3 (-2.5 to 2.1), Z-score FN -0.5 (-1.9 to 3.1) vs 0.2 (-1.2 to 1.4), both P < 0.05.

Patients with an ileostomy tend to have low body weight, BMI, LBM and BMD. They also tend to have low urine volumes, and some are depleted of Na, Ca and Mg. Abnormalities are greater in those with a lower urinary Na and measuring this will identify ileostomists at risk of Na depletion who will be benefitted by Na supplements.