crohn's disease to try complementary or alternative therapy. these include diets, probiotics, fish oil, and other herbal and nutritional supplements. acupuncture is used to treat inflammatory bowel disease in china, and is being used more frequently in western society. at this time, evidence is insufficient to recommend the use of acupuncture. a 2006 survey in germany found that about half of people with ibd used some form of alternative medicine, with the most common being homeopathy, and a study in france found that about 30% used alternative medicine. homeopathic preparations are not proven with this or any other condition, with large-scale studies finding them to be no more effective than a placebo. there are contradicting studies regarding the effect of medical cannabis on inflammatory bowel disease, and its effects on management are uncertain. prognosis crohn's disease is a chronic condition for which there is no known cure. it is characterised by periods of improvement followed by episodes when symptoms flare up. with treatment, most people achieve a healthy weight, and the mortality rate for the disease is relatively low. it can vary from being benign to very severe, and people with cd could experience just one episode or have continuous symptoms. it usually reoccurs, although some people can remain disease-free for years or decades. up to 80% of people with crohn's disease are hospitalized at some point during the course of their disease, with the highest rate occurring in the first year after diagnosis. most people with crohn's live a normal lifespan. however, crohn's disease is associated with a small increase in risk of small bowel and colorectal carcinoma (bowel cancer). epidemiology the percentage of people with crohn's disease has been determined in norway and the united states and is similar at 6 to 7.1:100,000. the crohn's and colitis foundation of america cites this number as approx 149:100,000; nih cites 28 to 199 per 100,000. crohn's disease is more common in northern countries, and with higher rates still in the northern areas of these countries. the incidence of crohn's disease is thought to be similar in europe but lower in asia and africa. it also has a higher incidence in ashkenazi jews and smokers. crohn's disease begins most commonly in people in their teens and 20s, and people in their 50s through to their 70s. it is rarely diagnosed in early childhood. it usually affects female children more severely than males. however, only slightly more women than men have crohn's disease. parents, siblings or children of people with crohn's disease are 3 to 20 times more likely to develop the disease. twin studies find that if one has the disease there is a 55% chance the other will too. the incidence of crohn's disease is increasing in europe and in newly industrialised countries. for example, in brazil, there has been an annual increase of 11% in the incidence of crohn's disease since 1990. history inflammatory bowel diseases were described by giovanni battista morgagni (1682–1771) and by scottish physician t kennedy dalziel in 1913. ileitis terminalis was first described by polish surgeon antoni leśniowski in 1904, although it was not conclusively distinguished from intestinal tuberculosis. in poland, it is still called leśniowski-crohn's disease (polish: choroba leśniowskiego-crohna). burrill bernard crohn, an american gastroenterologist at new york city's mount sinai hospital, described fourteen cases in 1932, and submitted them to the american medical association under the rubric of "terminal ileitis: a new clinical entity". later that year, he, along with colleagues leon ginzburg and gordon oppenheimer, published the case series "regional ileitis: a pathologic and clinical entity". however, due to the precedence of crohn's name in the alphabet, it later became known in the worldwide literature as crohn's disease.