[Prograde colonic irrigation without disturbance of the water-electrolyte balance]

The effects of four different irrigation solutions for preparation of colonoscopy were assessed in 64 patients. Using saline lavage solutions similar to plasma led to predominant symptoms of volume overload. Body weight transitorily increased by 1.7 +/- 0.2 kg, water and electrolytes were retained. Time until appearance of clear lavage fluid was 145 +/- 5 min. Irrigation by mannitol solution was badly tolerated and frequently led to vomiting. Body weight decreased and loss of water and electrolytes was reflected in changes of blood composition. Lavage with a hypertonic salt and mannitol solution (415 mosmol/l) was tolerated somewhat better. It led to minimal loss of weight, sodium (230 +/- 27 mmol) and chloride (270 +/- 24 mmol) were retained. Colonic cleansing was achieved after only 84 +/- 6 min. Isotonic saline mannitol solution with 105 mmol/l sodium, 93 mmol/l chloride, 10 mmol/l potassium and 22 mmol/l bicarbonate as well as 70 mmol/l mannitol (or 70 mmol/l polyethylene glycol) was tolerated best. There was a minimal weight increase (0.5 +/- 0.2 kg). Sodium metabolism was balanced (-2 +/- 7 mmol), chloride was retained to a slight extent (+ 115 +/- 29 mmol). Colonic cleansing was completed by 110 +/- 8 min.