One and a half year old tummy ache and crying at night may be related to indigestion, gastrointestinal cramps, enteritis and other conditions. 1. Indigestion: A one and a half year old baby may suffer from indigestion due to overeating or eating indigestible food, which may cause stomach pain and crying at night. 2. Gastrointestinal spasms: If a one-and-a-half year old baby suffers from spasmodic pain in the intestines due to cold weather or a cold stomach while sleeping, it may cause the baby to cry at night. 3. enteritis: enteritis can also lead to one and a half year old tummy ache crying at night, may also be accompanied by nausea, vomiting, diarrhea, fever and other symptoms. One and a half years old tummy ache at night crying may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause, under the guidance of the doctor to give targeted treatment or treatment.