Gastroenteritis

Gastroenteritis is a common cause of diarrhoea throughout the world. It is usually self limiting but in vulnerable individuals and severe cases it may be life-threatening. It is caused by an infection within the gut. It is a word used to describe the inflammation (“itis” ) which arises in the stomach (gastro-) and bowel (enter-) when it becomes infected with a range of organisms. These organisms may be viral, such as rotavirus, a common cause in children, or norovirus, (this is often called Norwalk virus, after the town where it was first identified). Norovirus is often the cause of winter vomiting epidemics. A range of bacteria and protozoa may also cause gastroenteritis. The commonest bacterial cause in Western Europe and the US s a bug known as Campylobacter jejuni .Other bacterial causes include Shigella, Salmonella, Staphylococcus  In elderly patients, who may have received antibiotics, C. difficle is relatively serious and common cause. Protozoa such as Giardia lamblia may also cause gastroenteritis, and this particular organism it may lead to ongoing symptoms of bloating erratic bowel habit and weight loss..

 

Gastroenteritis commonly presents with vomiting, nausea, colicky abdominal pain and diarrhoea, with frequent loose stools and urgency being common place. Whilst it is often self limiting and resolves within 24-72  hours it may last for several weeks, particularly in people who are infected with Campylobacter jejuni. However even in these people it usually resolves after a few weeks. Patients infected with Giardia often develop persistent infection and may suffer bloating, episodic loose stools and indolent weight loss. These symptoms often resolve slowly even with effective antibiotic treatment, because it takes time for the lining of the bowel to recover.

 

Treatment is usually based on ensuring people do not become dehydrated, oral rehydration is usually sufficient, sometimes using oral re-hydration fluids such as dioralyte (a mixture of water, salt which are lost in patients with vomiting and loose stools and sugar, which enables efficient absorption of the water). In exceptional circumstances and in those with pre-existing co-morbidities particularly kidney or heart disease hospitalisation and administration of IV fluids is required but such cases are the tiny minority of all those who contract gastro-enteritis.Where specific bacteria are known to be the cause specific antibiotics may be indicated, particularly in the immunocompromised. However in-appropriate antibiotic use should be discouraged and is usually contra-indicated in those with symptoms caused by E.coli 0157, where they may precipitate sudden decline in the patient’s condition. In patients with Giardia, specific treatment with either metronidazole (avoid alcohol with this drug!) or tinidazole in all patients.