Trial Outcomes & Findings for Bismuth Subsalicylate's Role in the Prevention of Travelers' Diarrhea (NCT NCT03535272)

Last Updated: 2026-05-22

Results Overview

Incidence of travelers' diarrhea, defined as self-reported occurrence of three or more unformed stools within a 24-hour period with or without associated gastrointestinal symptoms during travel or within 10 days after return.

Recruitment status

TERMINATED

Study phase

PHASE3

Target enrollment

482 participants

Primary outcome timeframe

Change from baseline through 10 days post-travel

Results posted on

2026-05-22

Participant Flow

Participant milestones

Participant milestones
Measure	Intervention Group Bismuth subsalicylate 4 tablets po bid (2.1 grams total of BSS) Bismuth subsalicylate: We aim to determine if there is a biologic benefit to an intervention (BSS administration) in the acquisition of travelers diarrhea and the acquisition of antimicrobial resistance genes.	Placebo Placebo oral tablet 4 bid Placebo Oral Tablet: Placebo manufactured to mimic pepto bismol
Overall Study STARTED	207	207
Overall Study COMPLETED	136	134
Overall Study NOT COMPLETED	71	73

Reasons for withdrawal

Reasons for withdrawal
Measure	Intervention Group Bismuth subsalicylate 4 tablets po bid (2.1 grams total of BSS) Bismuth subsalicylate: We aim to determine if there is a biologic benefit to an intervention (BSS administration) in the acquisition of travelers diarrhea and the acquisition of antimicrobial resistance genes.	Placebo Placebo oral tablet 4 bid Placebo Oral Tablet: Placebo manufactured to mimic pepto bismol
Overall Study Lost to Follow-up	71	73

Baseline Characteristics

Bismuth Subsalicylate's Role in the Prevention of Travelers' Diarrhea

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Intervention Group n=136 Participants Bismuth subsalicylate 4 tablets po bid (2.1 grams total of BSS) Bismuth subsalicylate: We aim to determine if there is a biologic benefit to an intervention (BSS administration) in the acquisition of travelers diarrhea and the acquisition of antimicrobial resistance genes.	Placebo n=134 Participants Placebo oral tablet 4 bid Placebo Oral Tablet: Placebo manufactured to mimic pepto bismol	Total n=270 Participants Total of all reporting groups
Age, Continuous	32 years n=2 Participants	32 years n=4 Participants	32 years n=6 Participants
Sex/Gender, Customized Male	51 Participants n=2 Participants	49 Participants n=4 Participants	100 Participants n=6 Participants
Sex/Gender, Customized Female	84 Participants n=2 Participants	85 Participants n=4 Participants	169 Participants n=6 Participants
Sex/Gender, Customized Missing	1 Participants n=2 Participants	0 Participants n=4 Participants	1 Participants n=6 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	12 Participants n=2 Participants	4 Participants n=4 Participants	16 Participants n=6 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	116 Participants n=2 Participants	123 Participants n=4 Participants	239 Participants n=6 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	8 Participants n=2 Participants	7 Participants n=4 Participants	15 Participants n=6 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=2 Participants	0 Participants n=4 Participants	1 Participants n=6 Participants
Race (NIH/OMB) Asian	13 Participants n=2 Participants	10 Participants n=4 Participants	23 Participants n=6 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=2 Participants	0 Participants n=4 Participants	0 Participants n=6 Participants
Race (NIH/OMB) Black or African American	24 Participants n=2 Participants	32 Participants n=4 Participants	56 Participants n=6 Participants
Race (NIH/OMB) White	73 Participants n=2 Participants	71 Participants n=4 Participants	144 Participants n=6 Participants
Race (NIH/OMB) More than one race	0 Participants n=2 Participants	0 Participants n=4 Participants	0 Participants n=6 Participants
Race (NIH/OMB) Unknown or Not Reported	25 Participants n=2 Participants	21 Participants n=4 Participants	46 Participants n=6 Participants
Region of Enrollment United States	136 participants n=2 Participants	134 participants n=4 Participants	270 participants n=6 Participants
History of travelers' diarrhea	136 Participants n=2 Participants	134 Participants n=4 Participants	270 Participants n=6 Participants

PRIMARY outcome

Timeframe: Change from baseline through 10 days post-travel

Outcome measures

Outcome measures
Measure	Intervention Group n=136 Participants Bismuth subsalicylate 4 tablets po bid (2.1 grams total of BSS) Bismuth subsalicylate: We aim to determine if there is a biologic benefit to an intervention (BSS administration) in the acquisition of travelers diarrhea and the acquisition of antimicrobial resistance genes.	Placebo n=134 Participants Placebo oral tablet 4 bid Placebo Oral Tablet: Placebo manufactured to mimic pepto bismol
Traveler's Diarrhea	27 Participants	26 Participants

SECONDARY outcome

Timeframe: Once within 7 days (before travel); once within 10 days (after travel)

Pre- and post-travel stools will be tested for the presence/absence of AMR genes. Data for this outcome measure are not yet analyzed. Results will be submitted when analyses are complete.

Outcome measures

Outcome data not reported

Adverse Events

Intervention Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Kristina Angelo

Centers for Disease Control and Prevention

Phone: 404-718-4876

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place