OBJECTIVE: To analyze the current information about laser safety in retrograde intrarenal surgery (RIRS), focusing on the two main laser technologies that we use in urology, the holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and the thulium fiber laser (TFL).
METHODS: Narrative overview of the most relevant articles published in MEDLINE and Scopus databases about this subject.
RESULTS: TFL and Ho:YAG laser at similar settings (0.2 J/40 Hz) have similar volume-averaged temperature increase and the average heating rate increase proportionally to laser power, especially when high frequencies are used. Recent preclinical data, comparing both laser technologies at different laser settings, agreed that when the delivered energy increases in expenses of higher frequencies, the thermal damage increases too. Higher frequencies, despite of the rise of temperature in the irrigation medium, can cause accidental thermal lasering lesions.
CONCLUSIONS: The use of low frequency settings and a proper irrigation is critical to avoid thermal injury in endoscopic laser lithotripsy. In addition, the use of laser safety eyeglasses is recommended in Ho:YAG and TFL ELL.

BACKGROUND: Dietary fiber intake helps in the remission of ulcerative colitis (UC).
OBJECTIVE: To evaluate if there is an association between the amount of fiber in usual diet and disease activity in patients with UC.
METHODS: Cross-sectional study of a cohort of patients with UC. Dietary fiber intake was calculated and compared with the recommended amount (14 g/1000 kcal) with Mann-Whitney\'s U-test. Using Spearman\'s correlation coefficient, the number of relapses and the amount of consumed fiber were analyzed, and the relationship of dietary fiber consumption with disease activity was established by logistic regression.
RESULTS: The group without ongoing UC activity consumed a higher amount of dietary fiber (20 g, IQR = 18-26, p = 0.062), and 47% consumed more than the recommended amount; the logistic regression analysis showed that compliance with recommended fiber consumption was associated as a protective factor against UC current activity (OR = 0.227, p = 0.032). As for dietary fiber intake and the number of relapses within previous year, an inversely proportional correlation was observed (r = -0.399, p = 0.011).
CONCLUSIONS: Consumption of the recommended dietary fiber amount in the general population had a protective effect against UC activity in Mexican patients.
UNASSIGNED: La fibra dietética suplementada coadyuva en la remisión de la colitis ulcerosa crónica idiopática (CUCI).
OBJECTIVE: Evaluar la asociación entre la cantidad de fibra de la dieta habitual y la actividad de la enfermedad en pacientes con CUCI.
UNASSIGNED: Estudio transversal de una de cohorte de pacientes con CUCI. Se calculó el consumo de fibra dietética y con U de Mann-Whitney se comparó con la cantidad recomendada (14 g/1000 kcal). Con coeficiente de correlación de Spearman se analizaron el número de recaídas y la cantidad de fibra consumida, y la relación de esta con la actividad de la enfermedad mediante regresión logística.
RESULTS: El grupo sin actividad actual de CUCI consumió más fibra dietética (RIC = 18-26, p = 0.062) y 47 % consumió más de la cantidad recomendada; el análisis de regresión logística mostró que cumplir con esta se asoció como factor protector en contra de la actividad actual de la CUCI (RM = 0.227, p = 0.032). En la fibra y el número de recaídas en el último año se observó una correlación inversamente proporcional (r = −0.399, p = 0.011).
CONCLUSIONS: El consumo recomendado de fibra en la población general tuvo un efecto protector para la actividad actual de la CUCI en pacientes mexicanos.

BACKGROUND: Significant advances have been made in the knowledge and understanding of the epidemiology, pathophysiology, diagnosis, and treatment of chronic constipation, since the publication of the 2011 guidelines on chronic constipation diagnosis and treatment in Mexico from the Asociación Mexicana de Gastroenterología.
OBJECTIVE: To present a consensus review of the current state of knowledge about chronic constipation, providing updated information and integrating the new scientific evidence.
METHODS: Three general coordinators reviewed the literature published within the time frame of January 2011 and January 2017. From that information, 62 initial statements were formulated and then sent to 12 national experts for their revision. The statements were voted upon, using the Delphi system in 3 voting rounds (2 electronic and one face-to-face). The statements were classified through the GRADE system and those that reached agreement >75% were included in the consensus.
CONCLUSIONS: The present consensus is made up of 42 final statements that provide updated knowledge, supplementing the information that had not been included in the previous guidelines. The strength of recommendation and quality (level) of evidence were established for each statement. The current definitions of chronic constipation, functional constipation, and opioid-induced constipation are given, and diagnostic strategies based on the available diagnostic methods are described. The consensus treatment recommendations were established from evidence on the roles of diet and exercise, fiber, laxatives, new drugs (such as prucalopride, lubiprostone, linaclotide, plecanatide), biofeedback therapy, and surgery.

To gather current evidence on the use of fiber for constipation treatment in pediatric patients.
Systematic review with meta-analysis of studies identified through Pubmed, Embase, LILACS and Cochrane databases published up to 2016.
Randomized controlled trials; patients aged between 1 and 18 years and diagnosed with functional constipation receiving or not drug treatment for constipation; articles published in Portuguese, English, Spanish, French, and German in journals accessible to the researchers.
A total of 2963 articles were retrieved during the search and, after adequate evaluation, nine articles were considered relevant to the study objective. A total of 680 children were included, of whom 45% were boys. No statistical significance was observed for bowel movement frequency, stool consistency, therapeutic success, fecal incontinence, and abdominal pain with fiber intake in patients with childhood constipation. These results should be interpreted with care due to the high clinical heterogeneity between the studies and the methodological limitation of the articles selected for analysis.
There is a scarcity of qualified studies to evaluate fiber supplementation in the treatment of childhood constipation, generating a low degree of confidence in estimating the real effect of this intervention on this population. Today, according to the current literature, adequate fiber intake should only be recommended for functional constipation, and fiber supplementation should not be prescribed in the diet of constipated children and adolescents.