The first stage last for 3-12 hours. It is characterized by the passage of profuse watery stools. Soon solids material disappears from the stools which comprise almost clear fluid with flakes of mucous, giving them the classical rice-water appearance. The patient then starts vomiting. At first, food is vomited but soon only rice-water is vomited. Severe cramps in the abdomen and limbs develop from loss of salt.
In the second stage, there is collapse from dehydration. The body becomes cold, the skin dry and inelastic. The blood pressure is low or unrecognizable, the pulse rapid and feeble. Urine production stops and the patient may die of shock.
The third stage is the stage of recovery, either spontaneously or with treatment. The diarrhea decreases, the patient is able to take fluids and and the general condition rapidly improves.