If your baby cries intensely, shows extreme fussiness, has facial discoloring, body tension and have crying sessions at predictable timing, then your baby is suffering from colic. While the diagnosis of colic predominantly consists of ruling out other illnesses, you can be almost sure that it's colic if the crying pattern follows the Rule of 3. The Rule of 3 is - If your baby cries for 3 hours a day, for 3 days a week, for 3 consecutive weeks. The Rule eliminates all references to abdominal pain and focuses on establishing a threshold of what is 'too much' by calculating how long the baby cries.