Intestinal gas dynamics and tolerance in humans Jordi Serra, Fernando Azpiroz, Juan–R. Malagelada  Gastroenterology  Volume 115, Issue 3, Pages 542-550 (September 1998) DOI: 10.1016/S0016-5085(98)70133-7 Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 1 Method. Gas was infused in the jejunum and collected via a cannula fitted in between the buttocks and connected to a barostat. Secretion drainage and gastric venting were controlled by separate channels. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 2 Gas evacuation during continuous intestinal infusion of gas; dose-response study in different groups of subjects (n = 6–12). ♢, 1 mL/min; ▵, 4 mL/min; ○, 12 mL/min; □, 30 mL/min. Dotted lines indicate infusion rates. Note that gas evacuation paralleled the infusion rates. Sham infusion group (0 mL/min) has been omitted for clarity. Values are means ± SE. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 3 Individual gas retention after 3-hour intestinal gas infusion. Retained gas is (Volume Infused) − (Volume Evacuated). Note that in all subjects except the 6 represented by solid symbols, total gas retention was within the ±400-mL range; 5 subjects (triangles) did not tolerate completion of the study. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 4 Gas retainers. Individual data from 6 subjects with >400 mL of gas retention. ▴, 4 mL/min (n = 2); ●, 12 mL/min (n = 1); ■, 30 mL/min (n = 3). Note progressive gas retention, perception, and abdominal distention during intestinal gas infusion. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 5 Individual perception scores after 3-hour intestinal gas infusion. Five subjects (triangles) did not tolerate completion of the study; the 6 subjects with >400 mL of gas retention are represented by solid symbols. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 6 Individual abdominal distention after 3-hour intestinal gas infusion. Five subjects (triangles) did not tolerate completion of the study; the 6 subjects with >400 mL of gas retention are represented by solid symbols. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions

Fig. 7 Intestinal gas clearance. SF6 clearance related to gas evacuation at the different determinations during the studies. ▵, 4 mL/min (n = 3); ○, 12 mL/min (n =3); □, 30 mL/min (n = 4); determinations at the end of each study are represented by solid symbols. Data from 4 subjects who retained gas are not represented. Gastroenterology 1998 115, 542-550DOI: (10.1016/S0016-5085(98)70133-7) Copyright © 1998 American Gastroenterological Association Terms and Conditions