Recently lot of children have presented with chronic abdominal pain, It might have started with an episode of diarrhoea but sometimes only vomiting. Usually it’s viral in nature and depending on the involvement of the lower gut, you may or may not get diarrhoea.
Due to severe vomiting, the acid from the stomach erodes the stomach mucosa and lower Oesophagus (food pipe). This irritates the stomach when you eat food and triggers further nausea and vomiting. Some children only experience ongoing nausea and do not vomit. Their appetite goes down and they may actually loose weight.
Treatment, after confirmation of diagnosis, is to stop / reduce acid production from stomach by H2 receptor antagonist (eg Ranitidine) or Proton Pump inhibitor (eg Omeprazole). It may take up to 4 weeks for the erosions (ulcers) to get better and then the mucosa heals. Slowly the nausea gets better and appetite returns.
If their is no improvement, then serious causes may have to be ruled out by Endoscopy (by a Paediatric Gastroenterologist). Sometimes H Pylori (a type of bacteria), can be responsible for such symptoms and may need Triple Therapy including Antibiotics.