Irritable bowel syndrome and lactose intolerance: the importance of differential diagnosis. A monocentric study

European guideline on indications, performance, and clinical impact of hydrogen and methane breath tests in adult and pediatric patients: European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Neurogastroenterology and Motility, and European Society for Paediatric Gastroenterology Hepatology and Nutrition consensus

“…It depends not only on the degree of enzyme deficiency, but also on the lactose amount and other components of lactose-containing food, on sensitivity to chemical and mechanical gut stimulation, on gut motility and on differences in microbiota. 12,18,46,[84][85][86][87]112,[136][137][138][139][140][141][142][143][144] If symptoms develop in the first 60 min after ingestion of the test carbohydrate, functional dyspepsia related to visceral sensitivity to gastric distension and psychological factors should be considered.…”

A Narrative Review of Irritable Bowel Syndrome with Diarrhea: A Primer for Primary Care Providers

“…Establishing a diagnosis of IBS-D is important for patient reassurance and to minimize undue cost to the patient or health care system [26]. Given the symptom overlap between IBS-D and other disorders often encountered in primary care practices, consideration of other conditions can guide clinicians (Table 1) [20,[27][28][29][30][31][32][33][34][35][36][37][38][39].…”

“…Intolerances to carbohydrates, such as lactose and sucrose, can cause diarrhea [ 28 , 29 ] and can be ruled out by food elimination trials or, if not confirmatory, by breath testing. Lactose intolerance is a common condition that may be misdiagnosed as IBS, given the similarity in symptoms (e.g., diarrhea, flatulence; Table 1 ) [ 28 ].…”

“…Intolerances to carbohydrates, such as lactose and sucrose, can cause diarrhea [ 28 , 29 ] and can be ruled out by food elimination trials or, if not confirmatory, by breath testing. Lactose intolerance is a common condition that may be misdiagnosed as IBS, given the similarity in symptoms (e.g., diarrhea, flatulence; Table 1 ) [ 28 ]. After consuming a lactose-free diet for 1 month, patients with IBS and lactose intolerance experienced a decrease from baseline in both IBS and lactose malabsorption symptom severity scale scores [ 28 ].…”

“…Lactose intolerance is a common condition that may be misdiagnosed as IBS, given the similarity in symptoms (e.g., diarrhea, flatulence; Table 1 ) [ 28 ]. After consuming a lactose-free diet for 1 month, patients with IBS and lactose intolerance experienced a decrease from baseline in both IBS and lactose malabsorption symptom severity scale scores [ 28 ]. Sucrase-isomaltase (SI) deficiency also can cause symptoms of abdominal pain, bloating, and diarrhea [ 29 ], and SI gene variants have been associated with IBS in some patients [ 43 , 44 ].…”