Progress in Study on Symptoms of Irritable Bowel Syndrome and Intestinal Gas / 胃肠病学

Irritable bowel syndrome( IBS)is a commonly seen chronic functional bowel disease,the prevalence showed a rising trend in recent year in China. At present,the etiology and pathogenesis of IBS have not yet been fully elucidated,and may be related to intestinal gas. Intestinal gas is usually composed of 59% N2 ,21% H2 ,9% CO2 ,7%methane(CH4 )and 4% O2 ,in which H2 and CH4 are produced only by intestinal bacteria metabolism. IBS patients usually manifested as having abdominal distension and symptoms of flatulence,suggesting the occurrence of accumulation of intestinal gas. In recent years,the relationship between symptoms of IBS and intestinal gas has attracted much attention. This article reviewed the progress in study on symptoms of IBS and intestinal gas.

Association between Symptoms of Irritable Bowel Syndrome and Methane and Hydrogen on Lactulose Breath Test

Whether hydrogen and methane gas produced during lactulose breath test (LBT) are associated with symptoms of irritable bowel syndrome (IBS) is not determined. We aimed to investigate whether hydrogen and methane on LBT are associated with IBS symptoms. Sixty-eight IBS patients meeting the Rome III criteria for IBS, and 55 healthy controls, underwent LBT. The IBS subjects recorded their customary gastrointestinal symptoms on a questionnaire using visual analogue scales. LBT positivity was defined to be above 20 ppm rise of hydrogen or 10 ppm rise of methane within 90 min. Gas amounts produced during LBT were determined by calculating area under the curve of hydrogen and methane excretion. Symptom severity scores were not different between the LBT (+) IBS and LBT (-) IBS subjects and also between methane producers and non-methane producers. Gas amounts produced during LBT were not associated with IBS symptoms, except a weak correlation between total gas amounts and a few IBS symptoms such as bloating (r = 0.324, P = 0.039), flatulence (r = 0.314, P = 0.046) and abdominal pain (r = 0.364, P = 0.018) only in LBT (+) IBS. In conclusion, hydrogen and methane gas on LBT are not useful for predicting the customary symptoms and subtypes of IBS.

Síndrome do intestino irritável - diagnóstico e tratamento / Irritable bowel syndrome - diagnosis and treatment

Síndrome do Intestino Irritável (SII) é um transtorno funcional crônico do tubo digestivo, caracterizado pela presença de dor e/ou desconforto abdominal associados à alteração do hábito intestinal ou à modificação das características das evacuações. A sua etiologia permanece desconhecida, mas provavelmente é multifatorial. A prevalência estimada da SII na população geral é de 10 a 20%, acometendo predominantemente mulheres entre 20 e 40 anos. O diagnóstico é feito baseado na sintomatologia predominante, adotando-se critérios clínicos bem estabelecidos (Roma III). O tratamento visa aliviar o sintoma predominante. Os antiespasmódicos representam as drogas de primeira escolha para o alívio da dor e do desconforto abdominal. Os antidepressivos tricíclicos têm se mostrado superiores ao placebo para os pacientes com SII e predomínio de diarreia, e a loperamida é eficaz em reduzir a frequência das evacuações nestes casos. Para os pacientes com SII e predomínio de constipação ou forma mista, as fibras solúveis representam a primeira opção. Probióticos e novos serotoninérgicos representam outras opções terapêuticas promissoras. Relatamos o caso de uma paciente do sexo feminino portadora de SII com diarreia predominante.

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract, characterized by abdominal pain and change in bowel habit, with a fluctuating natural history. The exact etiology remains unknown, but it is unlikely there is a single unifying explanation. IBS affects 10-20% of the general population, with women 20-40 years old accounting for the majority of patients. The diagnosis should be made on clinical grounds, using Rome III diagnostic criteria. The clinical approach is based on treatment of the prevalent symptom. When pain predominates, antispasmodics are the first choice. Tricyclic antidepressants are more effective than placebo for patients with diarrhea predominant IBS, and loperamide is useful for reducing bowel frequency in this patients. Soluble fiber represents the first option in subjects with IBS and constipation or mixed IBS. Dietary integrators composed of probiotics and serotonin precursors are a promising therapeutic option. We report a case of a female patient with IBS-diarrhea predominant.