Introduction: Phenotypic diarrhoea (PD), also known as tricho-hepato-enteric syndrome, is a rare disorder with intestinal and extra-intestinal manifestations. Patients have low birth weight, facial and hair changes and a severe diarrhoeal illness, requiring parenteral nutrition (PN).

In this study, we reviewed outcomes for the largest UK cohort of patients with phenotypic diarrhoea born since 1996.

Methods: We reviewed the medical records of children with phenotypic diarrhoea cared for in our tertiary gastroenterology centre up to 31 December 2018.

Results: 12 patients (7 female, 5 male) were included. 2 patients died, one at age 2 years and one at 10 years, both due to respiratory complications secondary to infection. Median age of the surviving 10 patients was 12.6 years (range 3.7-22.2). Probabilities of survival based on the Kaplan-Meier method was 100% at 1 years, 92% at 5 years, 79% at 10 years and 79% at 15 years.

Median age of PD diagnosis was 11.6 months (range 2.9-114.8). Presenting symptoms included protracted diarrhoea (n=6), faltering growth (n=6), liver disease (n=3), choledochal cyst (n=1) and meconium ileus (n=1). 9/12 (75%) patients developed respiratory issues, including bronchiectasis (n=5). 1 patient had bronchiolitis obliterans, resulting in prolonged ventilation, intensive care stay and subsequent requirement for home oxygen. 9/12 (75%) patients had liver involvement, improving with age. 4 (33%) patients had cardiac abnormalities. All patients showed intermittently low immunoglobulin levels and suboptimal immune response to vaccines.

All 12 patients received PN, with 6/10 surviving patients weaned off. Median age PN stopped was 9.7 years (range 4.37-13.27); median PN length was 5.7 years (range 3.7-13.4 years). Probability of continuing PN based on the Kaplan-Meier method was 100% at 1 year, 80% at 5 years, 41% at 10 years and 21% at 15 years. Patients continuing PN receive it 3-4 nights/week. One patient restarted PN after 11.4 years to achieve pubertal growth. Patients had improved weight-for-age Z scores with PN but showed a decline (median -0.61, range -3.5 to -0.12) after PN stopped. The majority have short stature, following the lower centiles (0.4th-9th) for growth.

Conclusion: In our cohort, intestinal failure is temporary- half of our patients are off PN, with future plans to wean the remaining patients. Rather than intestinal failure per se, morbidity and mortality is largely caused by immune deficit and resultant infections.