Gastrointestinal (GI) disorders like non ulcer dyspepsia (NUD) and irritable bowel syndrome (IBS) remain major problems in the West. A substantial proportion of GI disease in India remains of infective origin, such as viral hepatitis.

Despite the advances GI treatments made available in the last 30 years some diseases still remain difficult to treat. "Therefore the field for drug discovery and development in the GI arena remains wide open for pharma companies and medical scientists to explore and target molecules," said Dr KD Bardhan, consultant physician and gastroenterologist at Rotherham General Hospital and professor of Gastroenterology, University of Sheffield.

The biggest therapeutic advances have been made in the treatment of peptic ulcer disease (PU) and gastrointestinal reflux (GER) disease: the former can be cured in the majority and the latter effectively controlled in most.

In fact, the first breakthrough was the development of the histamine receptor antagonists (H2RA) a class of drugs which substantially suppressed acid secretion are cimetidine and ranitidine. The next major development was the proton pump inhibitors (PPI). These drugs caused profound reduction in acidity which are omepraole, lansoprazole, rabeprazole and pantoprazole. Being more powerful than the H2RA, ulcer healing, symptom relief was more rapid. PPIs are today used principally for the treatment of GERD.

Dr Bardhan with colleagues from around the world was involved in the clinical trials which helped to establish the place of H2RA and PPI in therapy.

About 5 per cent of the Western population continues to suffer from chronic disorders of the digestive system; this proportion is likely to be similar in the 6.72 billion global population although the makeup of the different disorders.

In the West, along with NUD and IBS, there is growing awareness of liver abnormalities as part of the 'metabolic syndrome' associated with insulin resistance of which obesity is an important component, said Dr Bardhan who is in India for the 50th Alumni Reunion of his class, the 1958 batch of the Christian Medical College at Vellore.

There is as yet no effective drug therapy for IBS. Much effort was committed to developing drugs which modulate the 5HT receptors for this purpose. Alosteron, a 5HT3 antagonist launched for the treatment of diarrhoea-predominant IBS, was withdrawn because of side-effects, principally ischemic colitis. Tegaserod, a 5HT4 partial agonist developed for constipation-predominant IBS did not receive regulatory approval in Europe for the degree of benefit over and above placebo in the pivotal clinical trials was deemed small. Various drugs have been tried for NUD but none have been consistently effective. IBS and NUD are not life threatening; but through the symptoms and ill health they cause often can be life-restricting, added Dr Bardhan.