Tummyache after food. Tummyache after food could be from a vsriety fo reasons. Soemtems the child doe snto like ot be forced to eat& will fake the pain/ may develop it subconsciuosly. Bring it to your pediatrcian's attention as there could be variety of other reasons that are treatable. Also, constipated kids sometimes have pain after food, the distension of stomach activates the gastrocolic reflex& the urge to have bm.