Number of participants with early responses to guselkumab will be assessed using bowel urgency and reported via participant diaries. Bowel urgency from participants will be asked as yes or no.

HBI score is used to assess disease severity and treatment effectiveness. The HBI consists of a 5-part questionnaire, assessing general wellbeing, abdominal pain, number of liquid stools per day, abdominal mass and complications. Clinical response for CD is defined as the HBI score less than or equal to (<=) 4 or a decrease in HBI by greater than or equal to (>=) 3 from baseline.

Mayo scoring system is used to assess disease severity and treatment effectiveness. The PMS comprises 3 categories: rectal bleeding, SF, and physician assessment. These are rated from 0-3 and are totaled to give a total score that ranges from 0-12. Clinical response for UC is defined as the PMS score less than (<) 4 or >= 30 percent (%) reduction from baseline.

HBI score is used to assess disease severity and treatment effectiveness. The HBI consists of a 5-part questionnaire, assessing general wellbeing, abdominal pain, number of liquid stools per day, abdominal mass and complications. Clinical remission for CD is defined as the HBI score <= 4.

Mayo scoring system is used to assess disease severity and treatment effectiveness. The PMS comprises 3 categories: rectal bleeding, SF, and physician assessment. These are rated from 0-3 and are totaled to give a total score that ranges from 0-12. Clinical remission for UC is defined as the PMS < 2 and a rectal bleeding subscore of 0.

Corticosteroid-free clinical response for CD is defined as a reduction in HBI by >=3 points from baseline or achieving HBI <=4 with no use of corticosteroids for at least 30 days.

Corticosteroid-free clinical response for UC is defined as PMS <4 or >=30% reduction from baseline and no use of steroids for at least 30 days.

Corticosteroid-free remission for CD is defined as no use of steroids for at least 30 days and a HBI score <=4.

Corticosteroid-free clinical remission for UC is defined as a PMS score of <2, no use of corticosteroids for at least 30 days and a rectal bleeding subscore of 0.

Corticosteroid-free PRO-2 remission in CD participants is defined as an abdominal pain (AP) score <=1 and a mean stool frequency (SF) score <=3 and no worsening of AP or SF compared with baseline and no use of steroids for at least 30 days.

Corticosteroid-free PRO-2 remission in UC participants is defined as a SF score of 0 or 1, where it has not increased from baseline, and a rectal bleeding sub score of 0 with no use of steroids for at least 30 days.

Characteristics of participants (age) receiving guselkumab treatment will be reported.

Characteristics of participants (sex) receiving guselkumab treatment will be reported.

Characteristics of participants (smoking status and history) receiving guselkumab treatment will be reported.

Characteristics of participants (height) receiving guselkumab treatment will be reported.

Characteristics of participants (weight) receiving guselkumab treatment will be reported.

Characteristics of participants (age at diagnosis) receiving guselkumab treatment will be reported.

Characteristics of participants (disease duration) receiving guselkumab treatment will be reported.

Characteristics of participants (disease severity at index) receiving guselkumab treatment will be reported.

Characteristics of participants (comorbid diagnoses) receiving guselkumab treatment will be reported.

Characteristics of participants (history of UC/CD) receiving guselkumab treatment will be reported.

Characteristics of participants (previous IBD medication use) receiving guselkumab treatment will be reported.

Characteristics of participants (Previous IBD-related surgeries) receiving guselkumab treatment will be reported.

An adverse event is any untoward medical occurrence in a participant administered a medicinal product based on appropriate medical judgment. An AE does not necessarily have a causal relationship with the treatment. An adverse event can be any unfavorable and unintended sign (including an abnormal finding or lack of expected pharmacological action), symptom, or disease temporally associated with the use of a medicinal product, whether or not related to that medicinal product.

An adverse event is any untoward medical occurrence in a participant administered a medicinal product based on appropriate medical judgment. An AE does not necessarily have a causal relationship with the treatment. An adverse event is considered drug-related if there is at least a reasonable possibility that the study drug contributed to the event.

An adverse event is any untoward medical occurrence in a participant administered a medicinal product based on appropriate medical judgment. An AE does not necessarily have a causal relationship with the treatment. An SAE is any event that results in death, is life-threatening, requires or prolongs hospitalization, causes significant disability, or is otherwise medically significant.

An adverse event is any untoward medical occurrence in a participant administered a medicinal product based on appropriate medical judgment. SAE is any event that results in death, is life-threatening, requires or prolongs hospitalization, causes significant disability, or is otherwise medically significant based on appropriate medical judgment. An SAE is considered drug-related if there is at least a reasonable possibility that the study drug contributed to the event.

CRP normalization is defined as as <= 5 milligrams/litre (mg/L) since baseline (among participants with elevated CRP at Baseline).

Change in CRP levels since guselkumab initiation will be reported.

Number of participants with fecal calprotectin normalization will be reported. Normalization is defined as percentage of fecal calprotectin (fCAL) <=250 micrograms/gram (mcg/g) since baseline (among participants with Calprotectin elevation at Baseline).

Change in Fecal calprotectin levels since guselkumab initiation will be reported.

Change in Leukocytes count will be reported.

Change in hemoglobin levels to assess anaemia will be reported.

Change in transferrin saturation Levels to assess anaemia will be reported.

Change in Ferritin Levels to assess anaemia will be reported.

Number of participants receiving concomitant IBD medications during guselkumab treatment will be reported.

Change from baseline in HRQoL for CD will be measured by PRO-2 components. The CD PRO-2 consists of 2 items: abdominal pain (AP) and stool frequency (SF). AP is a numeric variable with a score between 0-3 and is self-reported by the participant for the 3 days preceding assessment as 0 (no pain), 1 (mild), 2 (moderate) or 3 (severe pain). SF is also a numeric variable calculated the number of liquid stools a participant has experienced over the past 3 days.

Change from baseline in HRQoL for UC will be measured by PRO-2 components. The UC PRO-2 is composed of rectal bleeding and stool frequency. Rectal bleeding is a numeric variable with a score between 0-3 and is self-reported by the participants for the 3 days preceding assessment as 0 (None), 1 (Streaks of blood with stool in less than half of the cases), 2 (Obvious blood with stools in most cases) or 3 (Blood alone passes). SF is also a numeric variable calculated the number of liquid stools a participant has experienced over the past 3 days.

Change from baseline in HRQoL as measured by bowel urgency will be reported. Bowel urgency from participants will be asked as yes or no.

SIBDQ is a HRQoL tool measuring physical, social, and emotional status in IBD participants. The SIBDQ offers a broader evaluation of IBD-specific QoL across ten dimensions, including digestive, physical, emotional, and social aspects. The SIBDQ consists of 10- item survey measuring HRQoL over the last 2 weeks (frequency of bowel movement, abdominal cramps, fatigue, lack of energy, worry of surgery, fear of no toilet, ability to relax, irritability, impact on leisure, impact on intimacy). The total score ranges from 10 to 70, where high score indicates better QoL.

FACIT-F consists of 13 items to characterize fatigue symptoms and their impact on daily activities and function. It includes items such as tiredness, weakness, listlessness, lack of energy, and the impact of these feelings on daily functioning (for example, sleeping and social activities) over the last 7 days. The total FACIT-F score ranges from 0 to 52, with a higher score indicating less fatigue.

TSQM-9 is an abbreviated version of the 14-item TSQM, and is a reliable and valid measure to assess treatment satisfaction. It consists of 9 items distributed in the domains: side effects, effectiveness, convenience, and global satisfaction, with scores at each domain ranging from 0 to 100. with higher score indicating higher treatment satisfaction.

WPAI assesses impairment of work and regular activities due to overall health and symptoms. WPAI measures past-7-day work and activity that impact in Scores range from 0% (no impairment) to 100% (complete impairment); higher = worse. Absenteeism, presenteeism, and overall work impairment are for employed participant and activity impairment is for all participants.

The PROMIS 8b is a questionnaire based on the PROMIS sleep disturbance and sleep-related Impairment item banks. It contains the 8 best-performing items of these banks belonging to categories relating to qualitative, quantitative, behavioral, and symptom based dimensions of sleep and was found to provide greater measurement precision compared with other assessment instruments.

s-CS-IBD is shortened version of the CONFIDE questionnaire (Short-CONFIDE Survey for IBD consisting of 5 selected questions to better understand how IBD impacts sexual activity and if guselkumab treatment can improve this situation.

Endoscopic response is defined as 50% improvement from baseline in SES-CD total score, or SES-CD total score <= 4.

Endoscopic remission is defined as SES-CD total score <= 4 with at least 2 points reduction from baseline and no sub-score >1 in any individual component.

Endoscopic Improvement is defined as a Mayo score <=1.

Endoscopic normalization is defined as a Mayo score =0.

Histologic improvement is defined as neutrophil infiltration in < 5% of crypts, no crypt destruction, no erosions and ulcerations or granulation tissue according to the Geboes grading system, that is, Geboes score <=3.1.

Histologic remission is defined as the absence of neutrophils from the mucosa (both lamina propria and epithelium), no crypt destruction, no erosions, and ulcerations or granulation tissue according to the Geboes grading system, that is, Geboes score <=2B.0.

IUS Response is defined as reduction of bowel wall thickness (BWT) of >= 25% or normalization (<= 3 millimeter [mm]) of the most affected segment in participants with increased BWT (>3 mm) at baseline.

IUS Remission is defined as Normalization of BWT (<=3 mm) and vascularity (no signal or short signal in color Doppler of the most affected segment) in participants with increased BWT (>3mm) at baseline.

Change from baseline in the number of emergency room visits for treatment of UC/CD will be reported.

Change from baseline in the number of hospitalizations for treatment of UC/CD will be reported.

Change from baseline in the number of surgeries for treatment of UC/CD will be reported.