Gastro-intestinal Disorder diseases or maladies of the stomach and intestine. The human alimentary canal is a system that consists of a continuous long tube along which the ingested food is digested both through physical processes and through chemical reactions. It begins with the mouth and contains the esophagus, stomach, small intestine, and large intestine, which mainly aid in mechanical digestion of food although the salivary gland and the pancreas produce digestive enzymes, ending with the rectum and the anal region. With these, other accessory organs are connected, such as the liver and the gallbladder that produce and store the bile.

The different parts of the gastro-intestinal system particularly mouth, stomach and intestine are subjected to direct physical contact with external material taken as food and drink, and are thus susceptible to germ-related disorders carried by the material. The diseases of the stomach and the intestine are usually classified as gastro-intestinal diseases, while the diseases of the pancreas and the liver are treated separately.

Among the gastro-intestinal diseases, the most common is, historically, diarrhoea and other enteric infections caused by viruses, bacteria and intestinal parasites. Food and water contaminated with these agents are the primary source of entry of these pathogens in the gastro-intestinal tract. In poor countries, bad personal hygiene and poor sanitation practice often contaminates surface water such as ponds and rivers.

Diarrhoea accounts for the largest category of gastro-intestinal disorders in Bangladesh. An estimated 15% of all ailments is caused by diarrhoea, which mainly includes watery diarrhoea (cholera and other cholera-like bacterial and viral diarrhoea that produces watery stool and cause rapid dehydration of body), and bacillary dysentery which is characterised by bloody mucoid stool. Bacteria cause both of these types of diarrhoea. cholera and bacillary dysentery are highly endemic disease in Bangladesh showing high prevalence throughout the year, but every year these also occur as violent outbreaks affecting thousands of people and causing considerable morbidity and mortality. In addition, enteric fever such as typhoid and paratyphoid also constitute a significant fraction of disorders of the gastro-intestinal tract.

The next important disease of the gastro-intestinal tract is peptic ulcer in adults. Incidence of peptic ulcer is quite high in adult population of Bangladesh, accounting for about 7% of the reported cases of illness that are recorded by the country's government operated surveillance system. Conservative estimate of the number of peptic ulcer cases run to the order of some 3 million at present. Unfortunately, the disease shows a rising trend. Some peptic ulcer cases are known to transit into gastric cancer.

Diseases of the lower part of the gastro-intestinal tract such as the colon include the common condition described by the term Irritable Bowel Syndrome' (IBS), formerly called colitis. Symptoms commonly associated with this condition include abdominal pain, heartburn, flatulence and occasional ulceration of the stomach. Its incidence in Bangladesh appears to be quite high with high co-occurrence of the recently discovered bacterial pathogen Helicobacter pylori with such cases. A large fraction of IBS cases are perhaps included within the generalised peptic ulcer category reported by the government health care system in Bangladesh, but a large number perhaps remains unreported because of lack of active ulcer in these patients. [Zia Uddin Ahmed]