Thank you for your query at DoctorSpring.com.
Dear Parent,
I can empathise with your situation. Abdominal pain in children can be due to a variety of causes. The causes can be as benign as viral gastritis to more serious one such as intussusception or volvulus. The fact that he is having it only during the night means that it is only mild (he perceives it only when he is quiet and without distractions)
I would need a lot of information regarding the pain in order to be able to guide you any further:
1. Is it intermittent or continuous ?
2. Does it radiate or spread out in any particular direction?
3. How severe is it ? Does he cry out of pain? Does he wake up from sleep because of pain?
4. Whether it has any relation to food intake or stools?
5. Whether there is any recent change in the frequency or consistency of stools? Is there evidence of blood/ mucus flakes in the stools?
6. Is the child's appetite normal ? Does he have nausea ?
7. Is there any fever or other signs of infection?

The most common cause for peri-umbilical abdominal pain in children is worm infestation or non-specific colitis. The other more serious conditions need to be ruled out by clinical examination and if necessary, an abdominal ultrasonography.
Take care. Hope your child gets well soon.

Regards,
Dr. Saptharishi L G.
Consultant Paediatrician.