Introduction Intertwining of bowel loops to form a knot is very rare cause of intestinal obstruction. Among intestinal knots, ileoileal knotting is the most rare, with only a handful of cases reported in literature. We present a rare case of ileoileal knotting and review of small bowel knots. The aim of this review was to summarise the existing evidence on small bowel knots and to postulate the possible mechanisms for knotting. Methods A systematic search was conducted for literature published up to December 2019 using MEDLINE, PubMed and Google Scholar databases, together with the references of the full-text articles retrieved. Papers with case reports of small bowel knots were considered to be eligible for inclusion in the review. Findings A total of 14 case reports were evaluated. There was no clear predilection for age or sex. Mostly cases were from Asia and Africa with no cases from the West. The presenting complaints were abdominal pain (93%), vomiting (64%), abdominal distention (57 %) and obstipation (43%). The bowel was gangrenous in 78% of cases. All underwent exploration, with the majority requiring resection and anastomosis of the involved segment. Conclusion Ileoileal knotting is a very rare cause of intestinal obstruction. Possible mechanisms include loaded bowel with longer mesentery, vigorous peristalsis, single bulky meal, pregnancy and intussusception. The condition is extremely difficult to diagnose preoperatively and it is usually diagnosed intraoperatively. The standard of treatment is resection of gangrenous part and anastomosis.