It seems that you brother is experiencing gastro esophageal reflux disease (GERD). Stomach acid goes up in to the esophagus causing erosive oesophagitis and ulcers. Traditionally, anti-acid medicines are used to relieve symptoms. Although these can help ease the symptoms sometimes, they are not a long-term cure. If not treated effectively, an infant or adolescent can be reliant on anti acid medicines for long periods of time. Because medication has not proven successful in the long-term, the next option is a surgical procedure called 'Nissen Fundoplication'. This involves an operation on the abdomen through a reasonably large incision (unless performed via keyhole surgery, 'laparoscopy). The top of the stomach is wrapped around the esophagus (gullet) - making it act like a valve and stopping the reflux. The complication rate is 15-60% resulting in patients not being able to 'burp', swallowing difficulties and not being able to vomit. With a viral-like vomiting illness this can cause problems in itself. It should be a permanent surgical correction, but between 10-30% of patients will need the procedure to be repeated within 5 years.
However, there is now a new alternative using the endoscope via the mouth. With this new procedure - called 'Endoscopic Fundoplication'- there are no abdominal incisions at all and the operation is done through the Endoscope - through the mouth and it is easily repeatable if required at a later date, or easily undone if required. The Endoscopic Fundoplication procedure is done under a general anesthetic. Most patients are able to have this done as a day case or as an overnight stay. Following the operation, patients are advised to limit physical activity for the first 4 weeks and to avoid any contact sport. Anti sickness medication is required for 48 hours after the procedure and patients are told to avoid lumpy food for the first 4 weeks.
The long-term results of this procedure indicate that of 31 people, 3 had to have the procedure repeated at 1-3 years after the operation and 2 required the surgical fundoplication. Only 3 remain taking any medication. No medication is usually needed after the procedure and patients are usually symptom free.
About those laughter attacks, you can consult a neurologist; they are probably caused by his preexisting condition-cerebral palsy.