Up to one third of patients with Ulcerative Colitis (UC) will require hospitalisation for severe disease (ASUC - Acute Severe Ulcerative Colitis), often within the first 12 months of diagnosis. 30-40% of people admitted to hospital with ASUC will require colectomy during the emergency admission. Investigators will develop a multi-centre prospective inception cohort of patients with ASUC with homogeneously collected detailed longitudinal clinical, endoscopic and laboratory data.

ASUC can be a life threatening condition for which optimal management strategies within the acute setting are required. Such strategies remain largely ill-defined with approximately 30 - 40% of ASUC inpatient admissions requiring emergency colectomy.

Intravenous corticosteroids have been the mainstay of management during the inpatient admission but approximately 40% of this patient group will be steroid resistant. Although mortality following emergency colectomy has indeed fallen over time, it still remains as high as 10% at the 12 week marker. Patients with steroid refractory disease salvage therapy with infliximab can be considered to avoid colectomy.

Currently there are no predictive indices to identify patients needing rescue therapy. Hence health care professionals have no tools to 'personalise' care for ASUC by predicting up front which patients fail initial medical therapy and thus predict those who may benefit from rescue therapy or early surgery.

Traditionally the Truelove and Witts severity Index is used to define the clinical severity of disease on admission, but this long-standing index has yet to be validated as a predictor for the need for colectomy during the acute hospitalised phase. Similarly, endoscopic indices, including the only validated endoscopic severity score in UC (UCEIS - Ulcerative Colitis Endoscopic Index of Severity) have not been prospectively evaluated in the setting of ASUC.

Approximately 30% of ASUC patients treated with rescue anti TNF will fail to respond and require urgent colectomy. The optimal dosing regimes for rescue therapy with infliximab remains uncertain.Recently, there have been reports of increasing use of accelerated induction anti - TNF regimes in patients with ASUC (10mg/kg or shorter intervals) despite lack of clear evidence to support this practice. Randomised trial evidence for selecting patients suitable for accelerated induction regimes is not yet currently available and will require large sample size to elucidate clearly the variables that predict the need for individual dosing strategies.

Another consideration in the management of ASUC patients is the wide variability in practices among institutions and clinicians; this may potentially affect quality of care and outcomes within this cohort.

Investigators will develop a multi-centre prospective inception cohort of patients with ASUC with homogeneously collected detailed longitudinal clinical, endoscopic, laboratory and pharmacological data. This will facilitate development of risk prediction models in ASUC helping early risk stratification and supporting optimized medical and surgical algorithms in ASUC. The study will also facilitate development of a learning network in participating centres to improve quality of care.

Inclusion Criteria:

• age 18 - 80 years.
• Confirmed acute severe ulcerative colitis based on modified Truelove and Witts criteria requiring hospital admission.
• Need for at least 2 days of intravenous steroids
• Able to sign consent

Exclusion Criteria:

• Crohn's disease
• Admission for elective colectomy
• Infective colitis confirmed on stool culture, assays for C. difficile or cytomegalovirus
• Pregnancy
• Inability to sign consent
• Prior colitis related surgery - pouch, stoma

Hospitalised patients with Acute severe ulcerative colitis