An AE was any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. A SAE was any untoward medical occurrence (whether considered to be related to investigational product or not) that at any dose: results in death, was life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, was a congenital abnormality/birth defect, was an important medical event. Number of participants with AEs, related AEs, serious adverse events (SAEs) and related SAEs of retrospective observation period were reported.

Retrospective participants (RETRO): all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol.

Height was measured using age Z-score. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age greater than or equal to [>=] 2 years old) and World Health Organization (age less than [<] 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in height for age Z-score up to Week 168 of retrospective observation period was reported. Data for this outcome was not planned to be collected and analyzed in retrospective TED/TED group.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the retrospective TED/TED group.

Body weight was measured using age Z-score. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age >= 2 years old) and World Health Organization (age < 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in body weight for age Z-score up to Week 168 was reported. Data for this outcome was not planned to be collected and analyzed in retrospective TED/TED group.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the retrospective TED/TED group.

BMI Z-score was calculated by using the retrospective height and weight data. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age >= 2 years old) and World Health Organization (age < 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in height for age Z-score up to Week 168 of retrospective observation period was reported. Data for this outcome was not planned to be collected and analyzed in retrospective TED/TED group.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the retrospective TED/TED group.

TEAEs are defined as AEs that started or worsened on or after the first dose of teduglutide treatment in the core study. A SAE was any untoward medical occurrence (whether considered to be related to investigational product or not) that at any dose: results in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, was a congenital abnormality/birth defect, was an important medical event. AESI was an TEAE or TESAE of scientific and medical concern specific to the sponsor's product or program and for which ongoing monitoring and immediate notification by the investigator to the sponsor. Number of participants With TEAEs, treatment -emergent serious adverse events (TESAEs) and adverse events of special interest (AESI) of Prospective study period were reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria.

Height was measured using age Z-score. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age >= 2 years old) and World Health Organization (age < 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in height for age Z-score up to Cycle 6 Week 12 during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Body weight was measured using age Z-score. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age >= 2 years old) and World Health Organization (age < 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in body weight for age Z-score up to Cycle 6 Week 24 during the end of teduglutide treatment period of prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

BMI Z-score was calculated by using the height and weight data. Z-score was calculated as (observed value - median value of the reference population) / standard deviation value of reference population. Centers for Disease Control and Prevention (age >= 2 years old) and World Health Organization (age < 2 years old) Z-score calculation charts are used for calculation. A negative Z-score indicates values lower than the mean while a positive Z-score indicates values higher than the mean. Change from baseline in BMI for age Z-score up to Cycle 6 Week 12 during the end of teduglutide treatment period of prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Average total urine output was calculated based on the daily data recorded in participants diaries over a 48-hour period of nutritional stability prior to each scheduled visit. Average total 48-Hour urine output up to Cycle 6 Week 12 during the end of teduglutide treatment period of prospective study period was reported. Here, mL/kg/day is abbreviated as milliliter per kilogram per day.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Average total urine output was calculated based on the daily data recorded in participants diaries over a 48-hour period of nutritional stability prior to each scheduled visit. Average total 48-Hour urine output up to Week 108 during the end of NTT period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/TED group.

Average number of stools per day was calculated based on the daily data recorded in participants diaries over a 48-hour period of nutritional stability prior to each scheduled visit. Average number of stools per day up to cycle 6 week 24 during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data for this outcome was not planned to be collected and analyzed in prospective TED/NTT group.

Average number of stools per day was calculated based on the daily data recorded in participants diaries over a 48-hour period of nutritional stability prior to each scheduled visit. Average number of stools per day up to Week 120 during the end of NTT period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data were not planned to be collected and analyzed for the prospective TED/TED group.

Number of participants with positive specific antibodies to teduglutide were used to summarize the presence of antibodies.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure. Data for this outcome was not planned to be collected and analyzed in prospective TED/NTT group.

Number of participants achieved at least 20% reduction in PS volume at 12 weeks interval up to Week 156 in retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point.

Change from baseline in PS volume at 12 weeks interval up to Week 156 in retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point.

Percent change from baseline in PS volume at 12 weeks interval up to Week 156 of retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point.

Change from baseline in PS caloric intake at 12 weeks interval up to Week 156 of retrospective observation period was reported. Here, kilo-calories per kilogram per day was abbreviated as (kcal/kg/day).

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome and number analyzed signifies participants who were evaluable at specific time point.

Percent change from baseline in PS caloric intake at 12 weeks interval up to Week 156 of retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome and number analyzed signifies participants who were evaluable at specific time point.

Data for this outcome measure was not analyzed and collected because changes from baseline for prescribed hours per day were not collected at baseline in the core study.

Data for this outcome measure was not analyzed and collected because changes from baseline for prescribed hours per day were not collected at baseline in the core study.

Data for this outcome measure was not analyzed and collected because changes from baseline for prescribed hours per day were not collected at baseline in the core study. Hence, percent change was not assessed in this study.

Data for this outcome measure was not analyzed and collected because changes from baseline for prescribed hours per day were not collected at baseline in the core study.

Change from baseline in number of days per Week of PS usage at 12 weeks interval up to Week 156 in retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point.

Percent change from baseline in number of days per Week of PS usage at 12 weeks interval up to Week 156 in retrospective observation period was reported.

RETRO participants: all participants who consented to participation in this extension study and provided data for the retrospective period of the protocol. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point.

Number of participants who achieved at least 20, 50 and 75% reduction in PS volume at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Change from baseline in PS volume at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Percent change from baseline in PS volume at EOT of each cycle during the end of teduglutide treatment period in prospective study period.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Change from baseline in PS caloric intake at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Percent change from baseline in PS caloric intake at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Number of participants who achieved at least 100% reduction in complete weaning of PS volume at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Change from baseline in number of hours per day of PS usage at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Percent change from baseline in number of hours per day of PS usage at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Change from baseline in number of days per week of PS usage at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

Percent change from baseline in number of days per week of PS usage at EOT of each cycle during the end of teduglutide treatment period in prospective study period was reported.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

PedsQL GCS was used for quality of life assessment. It encompasses 4 dimensions of functioning (physical, emotional, social, school). Age groups are: Toddler (2-4 years), Young child (5-7 years), Child (8-12 years), and Teens (13-18 years). Depending on the participants age, the questionnaire may be completed by either the participant or the parent/caregiver as appropriate. For the Toddler group, the PedsQL GCS consisted of 21 items, using a 5-point Likert scale (0 to 4); for all other groups, the PedsQL GCS consisted of 23 items, with a 3-point Likert scale (0, 2, 4) for the young child, and a 5-point Likert scale for the child and teens groups. Scores are transformed on a scale from 0 to 100 where 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed signifies participants who were evaluable for this outcome measure and number analyzed signifies participants who were evaluable at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

PedsQL GCS was used for quality of life assessment. It encompasses 4 dimensions of functioning (physical, emotional, social, school). Age groups are: Toddler (2-4 years), Young child (5-7 years), Child (8-12 years), and Teens (13-18 years). Depending on the participants age, the questionnaire may be completed by either the participant or the parent/caregiver as appropriate. For the Toddler group, the PedsQL GCS consisted of 21 items, using a 5-point Likert scale (0 to 4); for all other groups, the PedsQL GCS consisted of 23 items, with a 3-point Likert scale (0, 2, 4) for the young child, and a 5-point Likert scale for the child and teens groups. Scores are transformed on a scale from 0 to 100 where 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Data was not collected and analyzed at this time point, for this respective arms.

PedsQL Family Impact Module was composed of 36 items comprising Physical Functioning (6 items), Emotional Functioning (5 items), Social Functioning (4 items), Cognitive Functioning (5 items), Communication (3 items), Worry (5 items), Daily Activities (3 items) and Family Relationships (5 items). Total score was calculated as the sum of all the items over the number of items answered on all the scales. Scores are transformed on a scale from 0 to 100 were 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, number analyzed signifies participants who were evaluable for this outcome at specific time point. Data were not planned to be collected and analyzed for the prospective TED/NTT group.

PedsQL Family Impact Module was composed of 36 items comprising Physical Functioning (6 items), Emotional Functioning (5 items), Social Functioning (4 items), Cognitive Functioning (5 items), Communication (3 items), Worry (5 items), Daily Activities (3 items) and Family Relationships (5 items). Total score was calculated as the sum of all the items over the number of items answered on all the scales. Scores are transformed on a scale from 0 to 100 were 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Data was not collected and analyzed at this time point, for this respective arms.

PedsQL GI symptoms module was composed of 58 items, comprised of 10 different symptom scales that assess gastrointestinal symptom-related quality of life: food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea. Only the scales of food and drink limits (6 items) and diarrhea (7 items) was used in this study. Subscale score was calculated as the sum of the items over the number of items answered in the scale. Scores are transformed on a scale from 0 to 100 were 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Here, overall number of participants analyzed refer to the participants evaluable for this outcome measure and number analyzed refer to participants evaluable for this outcome at at specific time point at specific time point. Data for this outcome was not planned to be collected and analyzed in prospective TED/NTT group.

PedsQL GI symptoms module was composed of 58 items, comprised of 10 different symptom scales that assess gastrointestinal symptom-related quality of life: food and drink limits, trouble swallowing, heartburn and reflux, nausea and vomiting, gas and bloating, constipation, blood in poop, and diarrhea. Only the scales of food and drink limits (6 items) and diarrhea (7 items) was used in this study. Subscale score was calculated as the sum of the items over the number of items answered in the scale. Scores are transformed on a scale from 0 to 100 were 0=100, 1=75, 2=50, 3=25, and 4=0. Higher scores indicate improved quality of life.

Safety population included all enrolled participants who provided informed consent for the prospective portion and met all the inclusion criteria. Data was not collected and analyzed at this time point, for this respective arms.