Megarectum rarely occur in adults. Rectal innervation abnormality or rectal muscle dysfunction could be the underlying pathophysiology, but there are cases where no specific cause is found. Only a handful of cases of megarectum in pregnancy were reported in the literature. Raised progesterone and reduced motilin level during pregnancy may affect bowel motility and predispose pregnant patients to this unusual condition. Clinical presentation ranges from bowel symptoms e.g. chronic constipation, nausea, vomiting and abdominal pain to dysfunctional labour including labour dystocia and obstructed labour. We hereby present a 23 year old lady in early pregnancy who presented with coital penetration failure due to megarectum. We wish to discuss the impact, outcome and management of this rare condition in pregnancy.